Refund request for equipment that was never used

I went into an Xfinity store interested in the self protection doorbell and lock and was told it would only be 10.00 a month plus the monthly installments of 10.00 for the equipment. 

when we received the equipment it was not suitable for our house so we returned it right away never used back to the same Xfinity store. 

A month later I receive a charge of 376.00 for an installment fee on equipment we never installed, or used and returned to the store. 

I immediately called Xfinity and they put an escalation ticket in. A couple days later they stated it was canceled so I went into the store and a manager said the employee who took the equipment back did not add notes stating it was returned. She attempted to complete the credit in person but was told by corporate that since it was over $300 it had to be approved by the revenue department. This was Wednesday of last week. It was supposed to be resolved within 3 days and it is going over a week. 

I called Xfinity today and was passed around from department to department. Home security said they could not credit because we do not have the home security service. Billing said they cannot complete the credit because home security added the charges. I waited on the line for almost and hour after requesting a Supervisor when the rep said it would be a 5 minute wait. I have never had such awful customer service especially this is Xfinity’s mistake. 

I need a Supervisor to contact me immediately to get this resolved.