More than Pathetic service from MTN

MTN has put me on Credit Score as In default. I have been a customer for over 9 years with a tablet - and just data renting from them. This is costing my credit score. I do not have any other accounts and all payments are up to date. I have an above average income. It is absolutely pathetic. I will NEVER deal with MTN in my whole life again and I will advise my colleagues, friends and family to do the same. Service is non-existent and unprofessional.