How do people dispute debit card purchases here?

I'm asking this for my SO, who used a UK debit card to order a new stovetop (hob) and installation from Curry'sPC. They screwed up the installation (chipped countertop, new hob not seated well). Apparently Curry's would only accept a debit card for the order. So far he has sent Curry's an email with photos of the installation and asked for a refund and that they repair the countertop.

I'm from the U.S. and only use U.S. credit cards. I don't use debit cards partly due to the ease of disputing purchases with credit cards. So...how do people dispute debit card purchases and obtain a chargeback in the UK once the merchant already has your funds? Given the general baseline of customer service in the UK, I'm not expecting a full-throated apology or refund from Curry's. But what can he try?

Also, has anyone filed a small claims suit in the UK? What was that like? Is there a resource that walks you through the steps? I'm a U.S. lawyer but have no clue how it works here...

Thanks!!!

I'm surprised that Currys wouldn't accept a credit card. Like you I prefer to pay on credit card for certain things knowing the additional protection, and then pay off in full when I get the statement.
Could contact citizens advice. Also, just posting up on the companies facebook wall often seems to get action as they are being publicly shamed.

I usually use my US c/card for larger items but here's a link on how to chargeback faulty items bought using a debit card:

http://www.which.co.uk/consumer-rights/problem/how-do-i-use-chargeback

There's also a phone number if your SO wants to talk to someone about the problem. Consumer rights are big here in the UK so your gf should be able to get a refund, its often the question of knowing the law.

This is way out of date now, but  moneyclaimonline - https://www.moneyclaim.gov.uk/web/mcol/welcome [nofollow]   is a good resource.

M.