NO reply to emails and NO answer

I called twice to cancel my contracts and each time Customer service puts me through to the cancellations department but no answer after holding for almost an hour in total. I sent an email to customer service a week ago asking them to cancel my contracts and still no reply. Both my contacts ended the beginning of this month but I want them to port my number to prepaid. If I lose my number or if they charge me or continue this contact with out my permission, I'll sue them as they I cannot get hold of them and after a week they don't have the decency to even reply to my email. Pathetic service. So glad both my contracts are done with them.