I don’t think he was trying to scam me, I said to just refund £5 since it sounded like it got lost in the post.
He kept saying no it wasn’t my fault and he would refund the full amount.
After all the excuses I’m not sure he sent them out in the first place.
I don’t really want to get his mate involved over £10.
Managed to get some adaptors elsewhere in the end!