I am not sure what to do now as the tx says it was double spent but when I asked the person who sent it to me they say they sont know what happened and that the btc wasn't returned to their wallet if it was dropped from the network.
He is lying to you.
If you look at the address is he sending coins from (
https://tradeblock.com/bitcoin/address/1FGJMzcAmN9PiwPSyG2FsYRTBchA8r7XWW), you can see multiple transactions where he sends coins to his own address. These transactions are for the exact same amounts he is "sending" to other addresses, yours included. The transaction to other addresses all have zero confirmations, while the transactions back to himself have hundreds of confirmations.
He is double spending his coins, so although it looks like there is a transaction coming your way, in reality he just returns in the coins to himself. No one can help you push or confirm that transaction because it has already been superceded by the transaction where he returned the coins to himself.
He is trying to scam you, presumably by trying to get you to pay him for the bitcoin he is "sending" you, even though it will never actually reach you. If you have already sent him money then unfortunately it is lost. If you haven't sent him anything yet, don't, and cut off all contact with this scammer.
In the future, if you are trading via localbitcoins, only trade ON localbitcoins. Don't accept offers from users who want to trade off the platform, as these are almost always trying to scam you, as in this case.