Hey @Nick9100 ,
Welcome to the Community .
If you have a prepaid service, there is no need to cancel. Simply stop refilling and your number will automatically be cancelled.
Just to make sure though, do you purchase a prepaid voucher or refill online? That would be prepaid, not to confuse with monthly services where you receive an invoice every month that you then have to pay.
Prepaid services are paid in advance or you will not have service. If you receive a monthly bill, you will need to contact us so we can cancel the service for you.
Let us know!