Bad service

I'm afraid to use Huawei any more due to pathetic service that I'm getting since my phone was broken,i submitted my phone for repairs and paid the amount they charged me suddenly when I collected it as they said it is fixed only to find out Dat it's no longer man its a Vodacombut but I bought it from mtn. When I returned it to find out why they said they will investigate and they promised Dat they will give me a feedback on Monday today it's Wednesday no feedbac as I was promised manager by the name of Hloni he is very useless he don't even fulfill his promises it's very unprofessional to hire a manager like him to present big company like this. Today you are promising to give me new phone and you don't even tell me what happened about your investigation. How come can you sell the Vodacom phone to mtn? Or maybe you changed the parts. You service its very bad, I'm also thinking to cancel this contract with mtm, now my wife she don't have phone we don't even able to communicate but we are paying for the service each and every month. I always want my petrol to come to your office and pay for paying because of your poor service