Bad service form MTN

I'm 15 years at MTN and have 7 numbers with them (4 data lines and 3 normal lines). 4 of my numbers are due to be stopped but they don't want to stop it I must pay for 2 months +- R9000.00 before they maybe wil cancel the numbers. I told them that I will pay that R9000 in Payments before it is stop. Now they stopped all my numbers and revues to put it back on again, they don't even give me a reason why they don't want to put it back on again.

What can I do now?

George Harmse *** (work nr)