Can one rightfully refuse to accept Mishloach manos based on the idea of one should not accept presents, or a person who does so wrong since shalach manos was instituted to promote love? The other reason for shalach manos is that it provides food for the seudah, so maybe the idea of not accepting presents can apply (and he should not accept it)?
The issue is discussed in the נזר התורה journal of Adar 5767, and in responses thereof.
Among the sources cited by the author are the following:
I. Responsum in Yizchak Burstein's מטעמי יצחק. There, R' Burstein cites Chulin 44b:
Whenever R. Zera was sent a gift he would not accept it but whenever he was invited out to dine he would go, for he used to say, ‘They are honoured by [inviting] me’. (Soncino translation)
R' Burstein explains that when the giver of the gift has some benefit (in the gemara, the sender would be honored if the esteemed Rabbi accepted the gift), the concept of שונא מתנות does not apply. Certainly, R' Burstein continues, by משלוח מנות where the sender is fulfilling a מצוה, the concept of שונא מתנות would not apply. (The discussion in the responsum is more detailed and complicated; what I've written here is just the essence of his argument.)
I would also add that the words of the Maharal (in נתיב העושר:א) are appropriate here:
והכל בודאי הולך אחר הכוונה, אם הוא שונא מתנות רק מכוין להחשיב הנותן שרי, אבל כאשר מכוין להנאת עצמו, בודאי האדם הזה יוצא מגדר מה שראוי אל התלמיד חכם
Everything follows the intent [of the recipient], if he despises gifts but he intends to give importance to the giver it is permitted. But when he intends for his own benefit, certainly that person departs from the bounds of what is befitting a Talmid Chacham.
I just found this answer(story):
The Brisker Rav Mulls Over the Mishloach Manos
It was close to sunset on Purim, and someone entered the house of R’ Velvel of Brisk with shalach manos. The Rav ran out of the house to see whether the sun had set yet. When the Rav came back into the house, someone asked him the reason for his puzzling behavior.
The Rav explained that he did not wish to accept presents under any circumstances due to the dictum, “One who despises presents will live” which is not a light matter. However, on Purim accepting presents stems from the din of shalach manos. Now that Purim was almost over, he wanted to check whether the sun had set, which would cause the shalach manos to become a mere present – which he was not willing to accept. (Chayim Sheyash Bahem) (www.Revach.net)