This does not surprise me, mercatox blocked dogecoin withdrawals for 2 years, I have $60000, at the time what was there was only worth $100. Told them I want to pay for a solution but they just ignore it and tell me to wait on social media.
The mercatox exchange solved the OP's problem after creating this thread. I emailed the mercatox exchange on Op's behalf and got a resolution to the complaint fairly quickly. Your funds have been stuck for so long why you did not take any action? If an exchange illegally withholds customer funds under any pretext, that is also a scam. Why haven't they taken proper action on Dogecoin after two years? Or did they sell your Dogecoin to another exchange?
I got into this in 2018, the problem actually started in 2020 with covid, many brokerages suffered from the same problem for short periods of time, I thought they would solve it, but until today they haven't solved it, I say it was a year, because talking to some people, they had access to withdraw.