If he's giving you the runaround, he obviously doesn't have it to give to you. My suggestion...if you want your money back talk to him, be upfront and maybe break the 300.00 up into two payments that might be easier for him to handle, something is better than nothing!
My Brother owes me money for a car he purchased. He keeps giving me the run around...What should I do if he doesn't pay me today? It's only $300.00.
He's probably giving you the run around because he lied about having the money to pay you back right away. Typical!
You may have to take him to court and have the big nasty judge order him to pay you.
Lesson to be learned here .. If someone doesn't have a good enough credit rating to get a loan .. Especially a small loan .. From a bank, what would make you think the risk would be any less for you?