8337351891

Called from fraud detection unit. I don't believe it's a scam. I used my card last evening and wouldn't go through.  After call and I confirmed I had tried to use it, she said ok, well take the hold off.  It's a fraud detection center.  My bank knows about it.

Maybe this was a valid call for you (assuming that you are not a shill for scammers spoofing this number), but is is possible that others receiving calls showing this number are not receiving them from an actual fraud detection service.
This number is used by a legitimate fraud detection service used by a number of credit unions and small banks, but criminals know that and they can spoof the number and pose as employees of the fraud detection service.
A good practice is to not take such calls at their word, but rather call your credit union or bank directly (at the customer service number on the back of your debit or credit card or a number published on their website) and ask to be transferred to their fraud detection department.

I received a phone call from Sierra Central Credit union credit card fraud. I checked the number and it's a scam.

Left a message which stated they were The Fraud detection center for my bank debit card number ending in **** They gave number. they wanted me to call regarding an 11 digit case number. so I call the 833 area code number ( because I recently had fraud and I reported it) so as soon as i call and the woman speaks ( with some foreign accent) I know its all Bull Chit! I hang up.