I was told that I was approved for a $750 advancement and once IRS accept my tax return. The IRS has accepted and I see no advancement on my credit karma spend card

Mine was approved for 3200 and accepted yesterday. I think we've been scammed 

The IRS is not officially accepting returns until Jan 27.  They are doing some test returns but that is not triggering an advance.

I agree. I guess we'll be getting a check in a few years after another class action lawsuit.