I would advise you to open a ticket on their website rather than sending email. I think they have some kind of weird anti-spam technique that may interfere with email, unless you get the right address - I'm not sure what it is.
Probably, there was either a mixup, or misunderstanding with the porting over of the number. Normally, their unlimited incoming calls plan is $2/month for each number (DID). So, I think what needs to happen is they need to merge the number you got on signup with the ported number.
Remember, most of these companies are very small operations, with a very low profit margin, so they can't afford to hire lots of support staff at the prices they charge. The definitely are not AT&T! If you expect similar service, then yes, you probably made a mistake and should regret it. But if you just try to be understanding, you'll probably find that it will work out. I'm sure you will not have to pay $2/month unless you want to keep both numbers.