Misunderstandings between what is "quoted" and what is actually done should not happen if quoted properly, but it does, and as the earlier post states, there is a difference between a quote and an estimate.
The other thing is you say you always give 12 months guarantee, how do you do this? is it a written guarantee offering more than the customers statutory rights? If you have just written, or you simply say, I give 12 months guarantee it is really worthless, as everyone who gives a service, supplies goods or materials by law must give a guarantee. The consumer statutory rights state the product or service has to be fit for purpose, and there is no actual 12 month time limit to this. This one year thing stems from suppliers, shops and retailers offering additional benefits to the statutory rights and they may be limited to 12 months. Everyone say's they give 12 months but this is really irrelevant. Your radiator install could start leaking after 2 years for example, and trading standards or a court may say that it would be reasonable to expect that the work you did should have lasted longer than 2 years so you are still liable.
Anyway, back to your post. If you go down the small claims route to get your money it is mostly done online now, but you need good evidence to support your claim. This will be written evidence, your quote, any emails, texts supporting the quote and possibly material invoices etc. But if you do not have good written evidence it is better to make a claim for consideration at the local county court, where you can both sit before the district judge. He/she will have already read and have a fair understanding of the claim and will listen to any verbal statements. So again it depends on what you wrote on your quote, what was said about doing additional work etc. The words "reasonable to expect" are very important, as a judge will look at the claim and make a judgment on what is reasonable that the customer would have expected to pay.
I hope this helps. Steve
