Small claims letter of intent refusal - England

I’m looking for some guidance, I’m currently trying to get back a few hundred pounds from someone who was a friend, I paid for a few things for him and he said he would pay me back. I have the texts where he says he would pay me back and nothing has happened, this has been going on all year now. I told him he had until the end of June to pay me before I started a small claims. No response so I sent him a letter of intent, he has refused delivery of this letter as I had it tracked and signed for. What are the ramifications of this? In the letter I gave him 14 days to pay me and from my research if he doesn’t respond within that time I can apply for a default judgement as I understand it, is this still the case? Basically what can I do now? Thanks in advance