866-245-8961

I dnt have checks or write checks of any kind no one has permission to any. Of belongings.Much less get a pay day loan

Receive a letter from ACE CASH EXPRESS saying a check was returned as 'FRG' by the financial Institution.  To please. call 866-245-8961.  I don't have any checks that might have been returned.  I think it's a scam.

I think the first thing I would want to know is what is "FRG".  Never heard of that.  Certainly do not call that number.  Ace Cash Express has a bad reputation and has taken to task by the CFPB.   That number doesn't appear on their website:  https://www.acecashexpress.com/customer-service
You have several options.  You can call them directly using the number on the above website.  You can send them a letter denying that the check is yours (should be sent certified, return receipt).  You can take the letter to the post office and have them forward both it and the envelope it came in to the Postal Inspectors.
You should also file reports here as well:
First, you should make a complaint at this Federal Agency, and while there you should also read up on how debt collection is supposed to work as well as what your rights in this matter are:  http://www.consumerfinance.gov/

Also file a complaint with your State Attorney General's office.
List of State AG’s offices:   https://800notes.com/faq/attorney-general

I forgot to mention, being that they are a payday lender.  That check cannot legally be considered a "hot check" since they accepted it knowing that it wasn't good at the time of acceptance.

Received a letter Dec 28th with the same claim from ACE CASH EXPRESS for a check returned "FRG" and to call phone number 866-245-8961.  Signed as "Bill Clark, Check Collection Specialist, Branch Location 3306 W Camp Wisdom Rd, Dallas, TX 75237".