MTN TERRIBLE SERVICE

I have a contract with MTN where I receive a monthly package, including 300 mb a month, after it finishes I purchase airtime or data packages, for the last 3 weeks it has been depleting in the space of 3 minutes, I am fuming with rage considering I have tried to get help 15 times from their customer service, I have cancelled subscriptions which don't go away, and have used my airtime to call their head offices where I was met the run around and connected to dead end help,I went in store to the pavilion where a guy dealt with the technical settings which may be taking my airtime which didn't help, I am sick and tired of MTNs poor services which have waisted my time, MTN has billed me to pay my outstanding balance but I refuse to pay a company who doesn't care about its customers. They have threatened to suspend my phone services in 2 days and want to force me to hold up my side of the deal while they send me running around looking for answers, il be damned. MTN buck up your performance otherwise we will leave you and go where we are respected as customers. I am livid.