If you (OP, or whoever you already represent here) did not request payment in ethereum, how the exchanger knows what your eth address is?
Is it 0x4c15B9B6E6177f20E745254758ed84b3e33a447E really belongs to you, I mean do you have access to funds on there?
if that entire amount still remains in your possession, this case cannot be characterized as fraud.
something completely different if they behaved unprofessionally and if they have caused you many complications during one round of exchange.
On telegram they have mentioned to send that address as a code which they have own. As a result we have no access of the fund. This case is not for unprofessional though the comment on bestchange about them is very unprofessional. This case is stands for fraud.