Mtn bad service

I’ve been treated unfairly by Mtn, I renewed my contract and I was supposed to get a SIM card only and they’ve offered a route as well, anyway I took it and now I’ve been charged monthly for that route of which I don’t have a problem with that, but my problem now is it doesn’t work and when I take it to their store I’m told that is an online thing. I need to contact the online services, and I’ve been trying to get hold of them and i can’t get hold of them the phone just cuts. It’s been 5months now. Please help ***