For example if someone in Islam today converted, and tomorrow they return back to any other religion, then:
Crime has been committed. And must be condemned His Actions will be punished
Is there any command about this in Judaism?
Provided the conversion was valid, the person is considered a Jew forever. If they "revert" to something other than Judaism, they may be sinning, but that is between them and G-d now.
As far as punishment, they are no different than any other Jew. That is to say, Jewish courts today no longer have the power to punish people for sins against G-d.
As HodofHod mentioned, once a person converts to Judaism, mentally and bodily, the conversion is full and effective spiritually and legally (meaning within Jewish law).
Aside from a few cases of very strict rabbinic interpretations of what is considered a "full and effective" conversion (and attempts, thereby, to retroactively invalidate a person's conversion), and different standards among different denominations, nobody disputes that once someone has effectively converted they remain Jewish, in the eyes of Jewish law, forever.
Just to add to that answer and clarify/expand a bit, there is no specific sin against "reverting", because no such thing is recognized. However, any time a convert engages in any act that is forbidden to Jews, the convert is sinning as a Jew by not upholding the commandments in the Torah - not because the convert has "reverted".