Sounds like you have been connecting either via Dynamic IP, some sort of shared connection (public WiFi at starbucks, college dorm etc) or perhaps a TOR/VPN connection and they seem to think that all these accounts are connected via IP. 
It has caught a few people out before... and it can be difficult to prove that accounts are not linked if they're only looking at IP data.
Try to remember to remain calm, and don't start getting angry or abusive. You're more likely to have a positive outcome if you stay calm and reasoned. They're also more likely to listen if this is the case! Good luck.
So far I am being quite calm. But it is becoming a bit challenging, it's the 3rd day and since the last email, no answer. I even asked yesterday if he had any update, and no answer so far.It has caught a few people out before... and it can be difficult to prove that accounts are not linked if they're only looking at IP data.
Try to remember to remain calm, and don't start getting angry or abusive. You're more likely to have a positive outcome if you stay calm and reasoned. They're also more likely to listen if this is the case! Good luck.