you need to provide more information if you want any help.
the bitcoin address that you received the funds in or the transaction id.
i am assuming that you are using Electrum since you posted here.
so did you download Electrum from its official website or did you download it from a fake website?
was the address created by Electrum or did you import it in?
do you have an updated antivirus / malware protection? check your computer with them.
from what I can tell it seems the same person who put the coins in took them back out. He says he doesn't even know hot to do that.
what do you mean?
did you actually receive the bitcoins in your wallet. i mean was the transaction confirmed?
or did you just see the transaction with 0 confirmation.
at the bottom left of Electrum the balance is like this:
unconfirmed transactions can be double spent!