It's been about 40 days since they have responded to me via email
here is their email.
Dear User!
We are sorry for making you wait for the answer. Our support team is overloaded, but we are keeping work on getting better response time.
Our pool was under huge attack in october and the billing system was corrupted with wrong amounts.
We have applied our hardest effort working 24/7 during this two months to get back
with the totally rewritten much more secure and robust code and now have reached an
important milestone - now all components of our new system are up and running.
All software was redesigned from a scratch.
We was able to migrate only user names and part of the workers.
In order to investigate your account we are asking you to provide all the information you have about the mining being held on your account:
1. Configuration of your PC or ASIC model.
2. Miner's settings you’ve used to connect to our pool
3. Any screenshots you have
4. All log files from your mining software
5. Approximately dates when you have used the service
Please send all the information to
pool@50btc.com.
Thank you for staying with us!
Best regards,
Miloslav Miloshevich
50btc support team