Well, if you already contacted them wait for weeks I believe they still respond but you will wait for many weeks before they reply to your tickets.
Actually, 3 months is too much but I have also login issue before but it was resolved in 2 weeks they said that they detected a suspicious login using my email and detects many wrong passwords. That is why their system automatically lock my account for security reason so I think this is the reason for other people or him that is why he is getting an error when trying to login with 2FA.
There is nothing we can do right now if Yobit is totally a scam they won't respond even in a month or so. Only support can help with this kind of issue but expect for months to get a reply from their support.