If a direct debit costs more than your balance, they refuse payment, and charge you £30 two working days later. If that £30 makes you go into the red, for some miraculous reason they find that somehow more acceptable. Funny, huh? Oh yeah, and for each month that you go into the red, there's an unauthorised overdraft fee of £28.
Some of that is fairly standard practice.
I'm with Halifax as well, it annoys me how they claim to be a bank but aren't. For example, a bank manager is considered an appropriate person to countersign a passport application. But Halifax's "bank managers" can't. They also have business accounts but don't provide business loans. They also have a credit card service that charges "repayments cover" proportional to the amount spent on the card, even though I pay off my bill every month without fail.
I nearly changed to Nationwide recently (who my parents are with), until they brought up a payment that they had neglected to bill my parents with 6 months previous (a Sky direct debit bill), and attempted to force my parents to pay it without providing proof that the bill hadn't been paid. Bear in mind... "direct debit", you know, the bill that your bank is supposed to handle? It's not like my parents have problems managing their finances, so the money has always been there to pay the bill.
Banks really p*ss me off. I'm not even going to go into the story of me trying to get a business loan, as it tends to make my blood boil.