mtn terrible service

Absolutely terrible service from MTN. I took out a data contract last year which required me to pay 2 months in advance for the data. Was not happy with the service and decided that i wanted to cancel the contract. instead of MTN cancelling my contract after the month which was paid for they suspended the service and requested another month payment before cancelling. this made it very difficult to cancel as i was not willing to pay for another month for a service that i was not going to receive. as i had already paid for a month way in advance and was suspended, i have to take MTN up to the Ombudsman to get them to cancel the contract and accept the router back. the router has been returned last year august but this year they smacked me with a bill of R2000+ stating the router was not returned besides the insurance they have been charging me for a device i do not have since last year. i have been running between the store and customer service for the past 9 months trying to sort this out the stores says they can not help it need to be done with customer service and customer service directs me back to the store. they are unable to give me names and contact numbers of accounts managers and it is quite frustrating. I have been applying for car finance recently and have been unsuccessful as i was unaware that this has been reflecting negatively on my credit record. if MTN does not have this sorted i will be forced to take this up further as it is now affecting my credit score and i am unable to make life improvements