Customer 1st Business Evaluation Services Mystery Shopper but scammed out of money Somis, California Nationwide

 Got an e-mail stating I had been selected for a mystery shopper job. Since I had applied for multiple jobs online recently I was not alarmed. The e-mail which has since vanished from my account said to expect a letter with a check. It came about one week later via priority mail. The check was for $2450.00 and I was to evaluate Walmart's new Walmart to Walmart money transfer. My contact was Alex Baker at 805-301-7203. The number is from Somis California but when he called to give instructions for my first assignment he sure sounded Nigerian to me. My bank cleared the check and the funds were available so I made the transfer. Then yesterday was notified by my bank that the check was returned. So now besides the $2450 they are charging $12 &$34 for the returned check and overdraft. I had a positive balance when I deposited check. The second task was to open a credit union account and get a cashiers check and a Walmart prepaid card and send the info to him at a gmail and yahoo address. This made me wonder but I got them now I have a $20 cashier check for a Sandra Thomas that I am not sure what I can do with. I did not send the second task info to Alex As this was when I first found out about check not clearing. I checked all I could it was drawn from a local credit union and was an official check. Luckily I made copies of everything and typed out all the text messages so hopefully something can be done but no contact has been made by Alex in two days now so I am guessing that he knows I figured it was a scam.