Terrible service for a big company

MTN service has been so terrible. I received a message stating I'm using a non compatible data device and my interest will be suspended, I then drove to a MTN store with the device only to find out the reason my internet was suspended it's only because I owe R11.50 fee due to a debit order that was rejected

When I paid this amount at the store I called MTN to have the suspension removed and you are telling me I have to wait for 24 hours to have my internet back on while I need internet to work.

You have the power to terminate my connection over fee I never agreed on, my monthly payment is R765.00 and I have no outstanding amount but yet my internet has been turned off.

Your service is bad for a huge company. I know this rant means nothing to you.