Is it ever ok to be impolite or rude. Say an employee is not doing their job or won’t help you when you paid for a service.
No it is never ok to be rude. As Jews, we have to set the standard and example for others.
Indeed, this was the difference between Yaakov and Eisav. The Zohar on Parshas Toldos writes:
וַיַּעַשׂ גַּם הוּא מַטְעַמִּים וְגו'. (בראשית כ״ז:ל״א) יָקוּם אָבִי, דִּבּוּרֵיהּ הֲוָה בְּעַזּוּת, בִּתְקִיפוּ רוּחָא, מִלָּה דְּלֵית בָּהּ טַעֲמָא, יָקוּם אָבִי. תָּא חֲזֵי, מַה בֵּין יַעֲקֹב לְעֵשָׂו, יַעֲקֹב אָמַר בִּכְסִיפוּ דְּאֲבוֹי, בַּעֲנָוָה, מַה כְּתִיב, (בראשית כ״ז:י״ח) וַיָּבֹא אֶל אָבִיו וַיֹּאמֶר אָבִי. מַה בֵּין הַאי לְהַאי, אֶלָּא, דְּלָא בָעָא לְאִזְדַּעְזְעָא לֵיהּ, מַלִּיל בְּלָשׁוֹן תַּחֲנוּנִים, (בראשית כ״ז:י״ט) קוּם נָא שְׁבָה וְאָכְלָה מִצֵּידִי. וְעֵשָׂו אָמַר, יָקוּם אָבִי, כְּמַאן דְּלָא מַלִּיל עִמֵּיהּ.
"And he also had made savory food...Let my father arise" (Bereishis 27:31). His speech was impertinent, rough, and impolite. Come and behold the difference between Yaakov and Eisav. Yaakov talked to his father humbly, with humility. It is written, "And he came to his father, and said, My father" (Ibid. 18). The difference between the language of Eisav and Yaakov is that Yaakov did not want to frighten him. Thus, he spoke humbly, saying "arise, I pray you, sit and eat of my venison." Eisav, however, said "Let my father arise," as if he was not speaking to him.
In fact, even if the person being spoken to is not particularly nice, or acts in an incorrect way that warrants a reaction, it is still not right to take a rude tone.
Refer to the Gemara in Brochos 7a where a known heretic would regularly upset Rabbi Yehoshua ben Levi, by challenging him on the legitimacy of certain verses. Rabbi Yehoshua ben Levi, had enough and planned to curse him at the point in the day where G-d's anger, as it were, flares, thus making it more potent. However, at the desired time he fell asleep. From there he concluded:
שְׁמַע מִינַּהּ, לָאו אוֹרַח אַרְעָא לְמֶעְבַּד הָכִי. ״וְרַחֲמָיו עַל כָּל מַעֲשָׂיו״ כְּתִיב
Conclude from the fact that I nodded off that it is not proper conduct to do so, to curse people, even if they are wicked. “His mercy is over all His creations” (Psalms 145:9) is written even with regard to sinners. (William Davidson translation & notation)
A final point to note is that not only is it incorrect to be rude or impolite but it also has an adverse effect.
Refer to Eruvin 54a:
(סִימָן: ״עֲנָקִים״ ״לְחָיָיו״ ״לוּחוֹת״ ״חָרוּת״). אָמַר רַבִּי (אֱלִיעֶזֶר): מַאי דִּכְתִיב ״וַעֲנָקִים לְגַרְגְּרוֹתֶיךָ״, אִם מֵשִׂים אָדָם עַצְמוֹ כַּעֲנָק זֶה שֶׁרָף עַל הַצַּוָּאר וְנִרְאֶה וְאֵינוֹ נִרְאֶה — תַּלְמוּדוֹ מִתְקַיֵּים בְּיָדוֹ. וְאִם לָאו — אֵין תַּלְמוּדוֹ מִתְקַיֵּים בְּיָדוֹ
In light of the previous discussion, the Gemara cites several expositions of verses proposed by Rabbi Eliezer, while first providing them with a mnemonic: Chains, cheeks, tablets, engraved. Rabbi Eliezer said: What is the meaning of that which is written: “And chains about your neck” (Proverbs 1:9)? If a person makes himself like a chain that hangs loosely on the neck, i.e., if a scholar is not pushy and disruptive to others, and he is also seen but not seen, i.e., just as a chain is covered by clothes and hair, so too, the scholar does not let himself be seen, his Torah study will endure. But if not, if he acts in a rude and arrogant manner, his Torah study will not endure. (William Davidson translation & notation)
The Ramban advises in his Iggeres Haramban (Sefaria translation taken from here):
Accustom yourself to always speak all of your words calmly, to every man and at every time. In doing so you will prevent your anger from flaring, which is a bad attribute in a man which may cause him to sin.
There is only one situation where one is allowed to be rude, and that is when mocking idolatry:
אמר רב נחמן: כל ליצנותא אסירא, בר מליצנותא דעבודה זרה — דשריא.
Rav Nachman says: All mockery is forbidden, except the mockery of idol worship, which is permitted [Megilla 25b]
Rav Ashi also says one is allowed to publicly mock a person who has a reputation of being a philanderer (following Rashi, R Steinsaltz).
Nowadays we don't have idolatry like in the gemara, and what we consider normal in today's society for a majority of people would be considered "promiscuous" by Rav Ashi's standards, so it's a question of if this still applies. I heard in a shiur that nowadays we would apply this to selfishness, which is a form of self-worship, as mocking the selfishness is a great way to highlight to a person how silly and childish they are being. CYLOR before applying this though!
Mockery is an insanely overpowered weapon - an extremely destructive one at that - so it must be weilded with extreme care in any permissible circumstances (which are few, if any), and generally avoided like we would avoid keeping a bomb in our possession.
Either way, none of this applies to your examples. Other answers have already explained at length that being rude is categorically forbidden in all such circumstances. The comments have raised that it might be ok to be rude to a corporation, but we wouldn't agree. A corporation is made up of valuable human beings who are just doing their job, and being rude to them is just as sacreligious as anything else (and generally doesn't help, it just makes the world a more sad, and stubbornly-angry place).