This isn;t another grilling at the royal mail (b******s

I sold my hideout a while back, and sent it recorded delivery
It never arrived
I've not got the receipt
I had to refund the guy (That's £55 I'll never see again

Due to my not having a receipt, is it even worth putting in a claim? Or will it just be a quick jobby of "you could be lying, so bu**er off"?