I've left a feedback on SirZelmer's profile. May I ask why you trusted him with BTC1.5 considering he's just a Full Member without any trusted feedback and on his last untrusted feedback he's being accused of scamming? Sorry to point out the obvious but you can always use escrow. If someone refuses using it then you can be sure he's trying to scam.
Probably you will need to post the whole conversion or further proof only if SirZelmer posts here with another version of the story. For the moment can you post the address where you were supposed to receive the coins along with the link to open it on the blockchain?