Ridiculous Debt I have no knowledge of!!

I am so appalled by how transunion and MTN have tarnished my credit score. First it is MTN not updating my payment to a Transunion report that claims I owe MTN R373800, can you freaken imagine? A whole R373800 for a phone contract? My credit score went down, my credit report reflects this big debt that is so wrong and transunion takes it as it is?? Do you not enquire first before you update these things? Please fix this mess! You are damaging my credit record!! And as for MTN I have already reported them to the ombudsman!!