Recently I changed a standing order with my bank (Abbey) this was done by handing in a new form at the branch. While looking through my statements the bank has been paying both the old and the new standing order causing me to go overdrawn. As the account has been overdrawn they have applied charges and any other payments that should have been paid have also been missed incurring more charges. Where do I stand on this and can a get the charges back?
The bank will archive a copy of your letter so you'll be able to prove their error and they'll refund all charges.
Even if they didn't, the charges are illegal so you could get them back anyway : see here and here.
Through the 2 letters that those sites encourage you to send, you are guaranteed a refund, even if the bank initially refuses (they're chancing their arm)