Legal department, Worst

I have a 24month cellphone contract with MTN, it got in arrears after I already paid 21months with only 3 months left pay. When I went to their offices to enquire about how much I owed with the intention of Paying off the debt, they said they cannot help me because my account been handed over to legal department. Then they advised me to contact their legal department which I've been trying to reach for months, its annoying because interest might be accumulating on my debt. I tried every number and even called their call centre. They promised to get back to me, it never happened.