Cannot use airtime when purchased with points

Hi firstly I've been with mtn now for many years and it seems that service has dropped terribly over the past few years.. Call center that does not answer when u in need of help!the number 808 is like a joke which just puts you on hold all the time with nobody answering! After 25minutes I'm still on hold every time! And most off all loyalty points that says u can use it on airtime but when I purchase the airtime it says no funds but do a balance check and the airtime is visible?? I am highly disappointed in this service such a big company but no customer service at all! Really really disappointing mtn...