Cellc Contract

My contract Ended on the 19th November 2020 and I immediately send them cancelation letter through their own channels that they provided, the I got a reply that the Metter has been escalated to the revelant department, the later I received another correspondence that I have a case number but I should expect delays because of covid-19, but I am still paying the contract even though it ended and I think they just giving an excuse for covid-19