Check with the gov website to check he is not a limited company.
If not (or he is), fill in a small claims court online for £25.00. If you have invoices etc, you will win. , this is because he has not denied the debt.
Give him seven days notice of suing ( mention that this will severely affect his credit rating for six years) and go for it, don't worry if he claims he was not warned, the postal rule covers that.
I suspect with his ego, you will be paid.