cancel a plan

My 92 year old mother has 2 accounts opened in error and I have been trying over the past 5 months via phone calls, chats and a local Xfinity office to get them to cancel the original account and keep the 2nd account., to no avail. The original account is on auto- pay and my brother, who opened the account for our mother cannot get them to cancel the account nor can he stop the auto- payments.  My mother cannot afford to pay double for the same service! Any suggestions?