*****ulent MTN contracts added to my Account

I’ve been ****med by MTN, someone added contracts/deals on my account with mtn and I have been struggling to get assistance to remove the unknown contracts. The bill keeps on piling up even though I have registered the case with MTN. Mind you I have been with MTN for more than 10years and suddenly people can just add deals and change payment methods without my approval or knowledge. I’m extremely disappointed. Their branches are very useless and unable to assist.