I couldn't answer Peter Pedant's answer above about a BACS charge for a failed Direct Debit payment, because I didn't think there should be any charge to the customer in these circumstances.
But even if there was a charge involved, I wouldn't know what that should be, as I think each bank seem to decide their own BACS charges.
Segilla - I think an urgent visit to your bank is in order. Paying by cheque should only be a short term answer, because if you do pay by cheque, make sure it's sent in good time, so that it can be cashed and cleared by the monthly deadline date that it's due. Also, be wary, some companies will only deal with Direct Debit transactions, and if try to pay by other means you could find there is an additional handling charge.
Segilla - I think a