Over the last few months I have seen 4 of my friends been perm banned because it had to do with some glitch on credits.
I asked them do they buy credits, they all said "No we get credits for our rares"
I noticed that the all got credits from 2 people (TizerTune,punksk8a1)
after a little mission to find out who these to were I found out that they are the same person.
So please if you do not want to get banned dont buy from TizerTune aka punksk8a1.