I'm sure it's very frustrating but issues like this are bound to happen and when they do, they usually catch the service provider off guard.

Bittrex is simply trying to abide by US law, in doing so it broke a few accounts and they did not expect as large of influx in tickets as the amount they have, clearly.

Hiring new staff does not happen over night, and hopefully Bittrex is taking the time to carefully select support staff that are qualified for the role and won't steal from the company or customers accounts.

In the mean time, they probably have a guys that are working on not just the exchange itself, but also doubling as the support staff to try to remedy the issue quickly.

Sending in a new ticket every day, will ONLY slow down this process MORE.

More time will be spent opening tickets, and looking for issues that can be solved quickly, only to keep coming across duplicate after duplicate where different support staff end up looking into the same persons issue.

Put in a ticket, understand the situation, be patient.

When they haven't got back to you in months, then yes, annoy the hell out of them with a daily ticket.
2-4 weeks is completely normal for blow up's like this, yes your funds are in there, but you accepted these potential issues when YOU put them there.