I have been successful with A&L, it doesn't matter how big or small the claim is the principle is the same so I'm sure you wouldn't have any problems getting it back.
As far as the wording for your claim is concerned, I just used the example wording in the templates section and altered it a bit for what I needed:
The claimant has had an account with the Defendant since July 2005. During this period, the Defendant has debited numerous charges to the account in respect of purported breaches of contract on the part of the Claimant.
The Claimant contends that these charges are punitive in nature and that the contractual provision that permits the Defendant to levy such charges is unenforceable by virtue of the Unfair Contracts Terms in Consumer Contracts Regulations (1999), the Unfair Contract Terms Act (1977) and the common law.
In remedy the Claimant seeks:
a) the return of the amounts debited in respect of charges since 26/09/05 in the sum of $437.00;
b) court costs;
c) The Claimant also claims
interest under section 69 of the County Courts Act 1984 at the rate of 8% a year from 26/09/05 to 21/04/06 of $8.38 and also
interest at the same rate up to the date of judgment or earlier payment at a daily rate of 0.12%
Obviously the dollar sign was put in as pounds!
Letter before action 
