Refusing to change my subscription fee

Poor customer service, I have been asking the company to change my subscription because the reason I upgraded it, I was advised by thier technician since I was expiriencing some issues with my internet we wanted to check if the issue was not caused bt the internet speed, the problem persistent i called them two weeks later and paid for the upgrade then later on I asked them to downgrade me because the upgrade is not helping, they said ok.. Come month end the amount of subscription is not changed i asked them nobody was willing to be accountable instead they would promise to get back to me ad never did, i sent them emails asking them help me, and internet became worse at home while I'm expected to pay big money for poor internet. It's the 5th month without help and internet is worse can't do anything with it.