Some time ago something similar happened to me with a Bitcoin betting method (something like Martingale system) in which the seller secured profit. Actually everything worked fine until I made a couple of greedy bets and lost some money. I fully understood that it was my fault, but I felt "cheated" (but the time has made me change my mind).
Regarding the refund of the money invested, it is somewhat complicated to verify, since with a couple of changes in the elements of a web page (something that an elementary school user could do) you can "modify" this amount invested, and that wouldn't be fair for the seller.
Anyway, even if the seller was honest and the method worked for him or he tried to scam people, is something that only he will know for sure.
Conclusion: Refund for the price of the method? If you have followed the steps and it does not work, yes. Refund of what was invested in the method? I would say no, unless there is obvious evidence of the amount invested (somewhat complicated in times of After Effects and Photoshop).