Chargeback in favour of buyer. What can I do now?

JetpackVelociraptor

I'm not sure what you think calling him is going to achieve with a phonecall, it sounds like he has no plan to work with you on this. I've been in a similar situation with my own business, and would definitely say that legal action is the best next step you can take. It's £2500, unless you're happy to write that off and let him get away with it you need to do something more than just ask him nicely.

If you don't want to deal with small claims, get your solicitor involved. If you don't have a solicitor, as a business that sells things of reasonable value it's important that you know a person/company who can deal with issues like this so now is the perfect time to go find one. Draft a letter before action confirming the timescale that the customer has to reimburse you for the goods, the fact that additional charges will be added to the amount you're claiming in line with your costs in recovering the money he owes you, and that you'll be taking further action if required. If you're not comfortable get your solicitor to write the letter. I'd also recommend getting them to skim through your Ts & Cs, there's a couple of things in there I'm not sure would hold up in practice - the restocking fee, the exclusion of shipping from the refund on returns, and the requirement to report any issues within 7 days all raise an eyebrow.

forgotmyname

Agree the terms and conditions are rather lacking.  The instruction/assembly manual may cause further issues.

You said it was custom, in what way was it custom?