I'm really disappointed in their service

I'm really disappointed in their service. Every month they make errors on my account and they don't attend to me immediately. Even when I try to call they will say they have escalated the matter but no one will call me from rain to follow up, instead I will have to call them again at my expense and be put on hold for 20minutes without any issues being resolved, or they say they will call me back but no one ever does. I'm really disappointed