Bad service of MTN store at BT Ngebs Mall, MTHATHA

I have a very horrible experience with MTN store at Mall of Mthatha ( BT Ngebs Mall). People work there are very unprofessional, rude, stubborn, not willing to learn or change, not customer friendly and not helpful. I approached the store to cancel a month to month home router contract in August. I got the advise from MTN customer service that month to month contracts are supposed to be canceled at the store. I returned my router in its original package and they accepted it and said they will book for cancelation. Also gave me an IRMS number. Two days later they sent the router back to MTN. It was done on the 18th of August. I contacted customer service several time and I am told that the store must cancel contract completely at their system. I went back to the store and relayed this message to them. They refused to do that saying that, they do not have that information from MTN. I called customer service while standing at the store and and they spoke over the phone even the store manager. They didn't agree to reach a concensus in this and still refused to cancel my contract. This excersise was repeated after a week and still these people are not willing to agree to their own company policies. It is making my life difficult as MTN continue to bill me for September and October while the router and simcard is back to them. I called an MTN store in Eastlondon and asked for advise. They also confirmed that what customer service is saying the correct information. Month to month contracts are supposed to be canceled at the store. Not telephonically. These people at Mthatha MTN store are deliberately doing this because they don't like customers who take contracts telephonically and they are not willing to assist. I am in deep trouble with this as I have returned the router at this specific store, I am unable to get help from another store. They are also care less because when they typed the IMEI number of the router on the Shipping document they made a mistake. I advise people not to use the service from MTN store in Mthatha Mall. Very bad service.