Transfer Market Ban

Got banned yesterday, I was playing and all of the sudden I couldn't open Market, I thought it was server maintenance or something, then I got an Email saying I got banned because of buying/selling coins which I had no idea that was even a thing, I was playing the game, yeah, I made some profits on the market but by just buying and selling players. I'm trying to appeal, let's see how it goes, but makes no sense, they killed the game for me, also they should give a warning or a 24h ban for example, If they tell me don't do this, I would 100% not do it, I did nothing against the rules, they even have a Profits tab on the mobile app, where you can check the profits you have made, so I don't understand at all.