An alternative theory would be the following: the OP said the tx was received2 weeks ago, so the transaction might have been valid... It's just no longer in the mempool of most nodes since it has been expired. At the moment, each recent node running with unmodified parameters will expire tx's from their mempool after 14 days, or if the mempool grows larger than 300 Mb. IIRC, older nodes will remove unconfirmed tx's from their mempool even faster.
This is just an alternative theory... Even if the tx was valid, there must have been a reason why miners didn't include it in their blocks.. Low fee, dust outputs,...
At any rate: if the op wants to have a shot at getting payed, he either needs to convince the sender to double spend the inputs of the "lost" transaction and fund his address again OR he has to get his hands on the raw tx... I did my part and checked my nodes, but the tx was not in my mempool (at least, not anymore).
EDIT: NOPE... I WAS WRONG... You were scammed
https://btc.com/2bbec1da63af69b4ff1fac46d27864abfe7fffa563e5c65b9fd2f65c453baaa5This dude spent the same input in this tx:
https://btc.com/6bc5ff43af1c893be9d908165a8a81e52c36f6ad4f5d7a95e7fd82a4fe838cb0He used a much higher fee for the double spending tx, and this double spending tx was included in a block 18 days ago...
I guess it might also be an honest mistake, but usually it takes a lot of effort to get a double spending tx included into a block, so the odds are not that good