Hey this statement is more useful than you think.
It seems like the problem was (accidentally?) brought by the Seller (Your trade partner for those particular trades),
If you can ask him to contact support regarding these transactions, you might solve the issue without contacting the customer support yourself.

And for Christ's sake, it's not "that" long since the last reply, I know a few exchange support where it always took weeks for the CS to respond.
But it's pretty obvious that the one you've contacted doesn't really know what he's doing (advised to use the chat to a suspended account  ).