Cancel my ct and pay back the debit orders for 2 years please

I have phoned twice to cancel a sim card contract that I havent used in approx 2 years or more, I dont even remember it was ages ago but the debit order has been happily been deducted from my account for the longest time. How many times must I phone to cancel? I am not using the sim card or the data or airtime for years! Please cancel.