Sharing your login credentials with everyone is probably against the tos.
Also, seeing lots of different ips trying to login to the same account could have made them assume your account was hacked, in which case disabling the account would be the right thing to do.
I do agree that not responding to your emails, etc is not cool.
Well, if they had seen this thread and had some bit of logic, they'd realize that people want that LTC and are going to be people from different IP's. You keep asking for your money, it's your's and not theirs regardless if it's their exchange.