@jk2 How long ago did you cancel? You’d normally get a refund within 5 working days to your bank if there’s an active direct debit otherwise you’d get sent a cheque which can take a bit longer to arrive.
@jk2 As far as I’m aware you won’t get a refund back to your credit card as it’ll either be to a direct debit or cheque. If your direct debit was active, check your bank statement for the money as it may already be returned. The reference may not show as ‘Plusnet’