cancellation

I requested sim swap since the 12th August 2022 and they said it’s gonna be delivered within then next 3 - 5 working days and it was never done or delivered then again on the 26/08/2022 I did the same request via Rain app (with ref no:*** and ***) still it was never done they I decided not to pay since there wasn’t anyone calling to update me the status of the sim swap. Now they don’t want to cancel my subscription tell me to pay before cancelling, why must I pay while they failed to deliver the services