MTN doesn’t want to Release my MTN Number from Contract to Pre-Paid after I have paid them

Hi my name is Potoko Abram Malebane I am customer I had a contract with MTN for more 10 Years on the 31 May my phone number was deactivated by MTN I called them trying to find out Why apparently I had 6 months not paying them then they are asked proof of Payment I have sent them. After that my Contract was cancelled without any communication.i have told them they will pay all the cost they cost my company since the number I use is for company use.is been 2 months fighting about with this issue no solution.i can’t even communicate with their legal department they keep blocking me to do so.i have requested my number to be removed from contract to pre paid ever since the contact is been cancelled. Is been 2 weeks with no luck just reference after reference.Truly speaking MTN is Ripping clients off if ur not Careful. I will never ever gonna recommend someone to open Contact with them.Thats a poor Network service company.Please help with this situation ???