Misleading sale - On Air continue to debit my account

I was offered a 2 year contract with On Air TV in June 2023. After I received the decoder I realized that the sale was misleading and I phone them to cancel the the contract. They have done an investigation to check if the sale was indeed misleading and came back to confirm that it was. The thing is - they debit my account for 3 months now and it's a struggle for me to get them to collect the decoder - the can only stop the debit order once they receive the decoder. I phoned them and was told that they tried to collect 3times and was unsuccessful now I'm bind in this contract. I only received a call once to inform me that they at my place for collection but that moment I was not at home. Now its a struggle to get them to collect the package its been draining me as I have to phone them email back and forth with no luck. Please help me!!