Please Help

Hello I'm new here, and I've got some problems with my Bitdefender Internet Security 2013 3PC's/2Y. I've bought it about 2 weeks ago, installed and registered on 2computers without any problems. Yesterday I was trying register and activate on 3rd one but every time it says that I don't have an internet connection and that my key was used, but it says that my licence is for 30days not 2 years... From main program can't even register onto my account and can't activate program. Can someone help me with that problem ? I've tried everythin, uninstall reinstall repair and always says that i don't have an internet connection.