if people can afford for IMU-PMS, i dont think they will want much of a reimbursement. lol anyway IMU doesnt allow that

So it sounds like you have already checked with IMU about this and they have allowed this trading.
However, even though there is someone who is willing to swap, there should be a waiting list.
It is not a matter of money or reimbursement, because this is not up to the student but the university.

there isn't a 'waiting list'......however, there is a 2nd selection (maybe even 3rd selection) list, where after the initial round of offers have expired and they know how many have rejected offers, they will offer the vacant places to the 2nd selection list......

there are also people who applied late after all places have been given out, but meet the 1st list cut off......they will be placed in the next batch 1st selection list..........