Poor service

Im very annoyed with the service MTN gave me ,firstly MTN decided to not debit my account last month Lord knows why and then yesterday they decided to double.debit me ,why does your billing.department not do their work and when they have not done so they wont even call to redress the issue ,MTN needs to know we budget each month ,they need to learn to hire competent people im just angry MTN cannot do as they wish on peoples accounts and decide to7 bridge the contracts this is utter nonsense totally dissapointed at you guys for the poor service