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.
Gather evidence of the problems you are facing and how they are giving you various excuses as to why they are not allowing you to withdraw. Here you can open an accusation thread against them, so that it can be helpful for others who are in the same problem as you. I think mercatox didn't want to miss this lucrative opportunity due to the reckless price increase of Dogecoin and played any hidden game with their customer's funds. It is important to know detailed analysis from them.