No, I have expertise that would have been used to resolve the problem. The folks at H&R Block charged you for expertise that can be had for free. If your expectation was that they were going to do something more than what you could do for free, and which took up the same amount of time as if you had done it yourself for free (probably more time, really, especially including travel), then I see no problem with rejecting their offer.

In fact, turn it around for a second. Say you did your taxes for free with TaxAct and you felt like a professional might do a better job. So you go to H&R Block expecting that they're going to provide you with their expertise to help. You get there and they effectively run through the same program you just did, asking you the same questions, and getting the same result. Would you be satisfied?

In addition, I wouldn't offer a guarantee of satisfaction up front.