Service plan horror

I had a Service plan with Standard bank. It expired 7 months ago and I called to cancel and to say that I don’t want to upgrade it. They kept on deducting and it’s been 7 months now. When I call them they send me back and forth. I’ve been using my airtime with no luck of being helped. No one bothers to return my calls when I run out of airtime, or email me or something. The Maintainance department confirmed that they owe me money for 7 premiums and sent me to the Vehicle asset department for a refund, and this department sent me to customer care . The customer care sent me back to the maintenance department. No one seems to know where I should get help. Please assist.