Have to pay for no service

I had problems with my internet speed upgraded from 2 mbps line to 4 mbps line. Never got close to 1.5mbps speed so i downgraded my internet again. Paid for the 2mbps line service and got billed for 4mpbs line when upgraded but never got the speed so went back to 2mbps line now my account has been suspended becuase of the differenc. I deem it unfair to pay for a service i did not get.