Delay in canceling my contract

Been trying to cancel my contract for the past 5 days . I keep getting agents asking me the same questions all the time with no solutions. Why is it that you so quick to help someone take up a contract but when I want to cancel I'm taking back and forth. Worst of all my contract ended in March but you didn't cancel it. Now my credit score is affected by this!!!! This is purely nonsense. I'm going to take this forward with Ombudsman and NCA commission. What kind of TCF is this!!!!!