Double account

Xfinity created two accounts for me when I signed up, and after several calls, the account still exists, and has now been sent to collections. I've just closed out my actual, fully paid account, but I can't seem to get someone in store or over the phone who can help me delete the erroneous account. This has made me 100% sure that I will never have another account with xfinity. It has been nearly 7 months with multiple communications both online and in store and it still has yet to be rectified. This is exhausting.