I unfortunately need to sue a builder, but all I have is his name, bank details, post code and phone number. What can I do?

This is someone who put a patio in my garden, which is falling apart a year later. He didn't do it via a company or anything, just as a sole trader. I've spent 7 months unsuccessfully trying to get him to come back and deal with it, which it seems he isn't going to do. I've sent him a letter before action via WhatsApp, which he has read and responded to (not positively). Problem is, I don't have any way of getting his home address. I don't even have an email address. All I have is his name (though he's used two different names), his bank details, his post code and his phone number. I've tried to use a tracing service to get an address, and they came back with nothing.

If this does have to go to court, presumably I'm going to need more details than I have. Anyone got any ideas of what I can do? And yes, I know that I should have initially got an invoice, quote and everything. Lesson learned, and I will be taking a lot more care in the future.

This is in England, by the way.

Thanks in advance for any help anyone might be able to offer!