Global Test Market Joe Coring $990 check to buy money pak and keep $120 for myself for being a mystery shopper Stamford, Connecticut

Got a check for $990 and a letter from a Joe Corning, Group Project Director and asked to deposit check and when it cleared the bank, purchase an $870 money pak at a Walmart and call them to answer the mystery shopper survey.  The number to call was 416-400-2706.  Turns out that is in Canada.  The business is listed in Stamford, CT and the check is on a bank in Bloomingdale, IL.   I called my bank to see if the routing number was a real bank and it was.  I called them and they could not verify if the acct was a real acct as that is confidential information.   However, he told me not to cash the check.  They get calls like this all the time and it is an old scam.