If you are on the month to month plan it will keep going until you call them up to cancel. If you are on the two year contract you won't be able to cancel with out the term fee.
Call them and say you want to suspend your account. The rep i spoke to was unckearif it was something you would need to do periodically or not. He said normally their plans only suspend for 90 days and then reactivate.
He was indicating he would want to reactivate later. If you cancel you would get popped the activation fee when you start back up. If you suspend you won't be paying and can pick it backup later with no activation fee. At least that was what customer service explained to me as the difference.