MTN POOR SERVICE OR LACK THEREOF!!!

I'm an unhappy customer soon to be a former. Each time I call 808 I hold on for 5 to 10 minutes then I get cut off without getting through to an agent, if I'm in luck I'll hold 30 to 45 minutes to speak to an agent. I did an upgrade in Feb and days later when I enquired on 808 was told it declined. Weeks later I got an SMS that delievery will be in 7 days I then called 808 to cancel the upgrade. In March I needed to make a payment I called 808 to realise that the upgrade fee and promo fees were not reversed as I thought it would be done automatically since I cancelled the upgrade ,and I was told I mustn't pay as the account has to be corrected. Till today my account is still not rectified. Despite numerous calls to 808, emails to customer care all I get reference nrs and promises that never happen. I want to cancel the contract, but I can't because no one at MTN can do their job.