- He has scammed you. He intentionally sold you codes that he knew were crap, and now is pretending not to have received the bitcoins so that he can avoid giving you anything back.
- He is inept. He didn't know that the codes he was selling you were bad, and he doesn't know how to operate his own bitcoin wallet. He has therefore either been hacked, has malware running on his computer, or simply screwed up by giving you the wrong address. He honestly can't access the bitcoins because he's got no idea what he's doing.
^^This. We can all clearly see (https://blockchain.info/tx/1a885393910d03c2cfe1a42e686277db1499111ce8f876f9fdcb885b4889c3cc) not only does the TX exist, and went through to and was received by the address 1GmQFe5vhMJJ4hfMoTNaoR5HJDVdHfh8Ye. Furthermore, those bitcoins have already been spent. If he didn't get them, either he gave you the wrong address or was hacked -- in either case 100% his fault and not yours at all. You can prove you sent it to the address, and that *someone* received as well as spend it. It is his fault if he gave you an address to pay to that someone else is in control of.