Horrible Service

I have called in numerous times to MTN to ask them to put my credit limit to R200 but every month i get a sms that my credit limit it is R754. I am tired of asking everytime as its a waste of time calling in everytime. This will be my last time i ask you guys MTN to set my limit to R200 permanently. Failure to do so will result in me terminating my contract permanently with you. Seems like you dont take your customers seriously