Unmastered scam

So, I bought a lot of packs on Warframe from the user "UnMastered" worth over 200$ and he seems to have charged back whatever he got and I have a negative platinum balance of 8000 now. I've tried to get in contact with him but I'm pretty sure at this point, he's just ignoring me. I don't really know what to do as I have to get my platinum back to positive to even log into my account. Is there anyone who could help me out here?

When I migrate my account from PC to Nintendo Switch. I was able to play my account again with all the negative balance removed, the good part too is I have all of the previous skins,frame,weapon,slots etc... still able to play it, but now it just on the switch. Once you migrate to Switch it is irreversible.