Cheapest way to charge amex and end up with cash/check?

I need to charge $40000 to my card over 5 months (for now the *why* is not relevant, but long story short it has to do with reaching status with Delta).

The problem is, I don't spend nearly enough to reach that number. Is there a third-party service that I can "purchase" 40000 from and be returned cash or check? I would be fine paying some overhead (for example even up to 3% might be fine given the benefits for me).