Unhappy client

Hi I would kindly like report my unhappiness with MTN service, I have been a client with you for more than 15years..last year November I was billed for roaming charges that I never signed for.. I then made an arrangement to pay back the amount monthly.. Every 5 days my line gets disconnected, I have to phone, beg them to open my line.. After they do the same again.. My mobile number is ***. I make it a point every month to pay my debts.. I do not remember signing any form telling about roaming charges..