Optical Express asking for money I do not owe

[usetheforce]

I used to get contact lenses from optical express but have now changed to another supplier. I have spoken to someone at Optical Express to ensure I owe nothing in terms of direct debits and i was told i do not owe anything.
As far as i am concerned I owe them nothing but they are claiming i owe £50.85p.
I know its not alot but the principality of this issue is more important.
The demands now are getting more aggresive and the last letter I got today threatened the issue of a County Court Claim as well as a Debt Collector coming to my house
What can I do. Are there any template letters I can use from this sire as I want to follow and strong procedure to kick them into shape

Many thanks in anticipation

	County Court guidebook by Judge Patricia Pearl Follow this link to read the review of this excellent Small Claims Guidebook. This comprehensive and very accessible guide will take you through the process of suing or defending a claim. This guide will help you take control of your litigation and make you more confident about doing it yourself. Applies to England and Wales

	Debt collection library Follow this link to our debt collection library. This library contains templates and advice for dealing with debt collectors who act oppressively or unfairly. This library is work in progress and will be built up over the next few weeks. 17.03.09

[freakyleaky]

You should ask them for details of the alledged debt. You want to see exactly what the debt applies to and then cross check it with your own records of payment.