After you file

You do realize that TurboTax and Credit Karma are part of the same company, Intuit?  Blaming one or the other does not really matter.  Credit Karma can't refund your money because you did not pay them anything.  Only TurboTax can do that.  But it all comes out of the same company's funds.  For the agent to try to blame one or the other shows that the agent does not know that the companies are the same.