Bills and accounts / Paying your bill / Direct Debit

1. How can I increase or change my Direct Debit payments?
2. How can I change my bank account details?
3. How can I change my Direct Debit details?
4. How is my monthly Direct Debit payment calculated?
5. Why have you increased my Direct Debit even though I am in credit?
6. How can I set up a Direct Debit?
7. How can I change the bank you collect my Direct Debit from?
8. Can I pay my bill by Direct Debit?
9. Can I change the date of my Direct Debit payments?
10. Can I cancel my Direct Debit?