Without inspecting the logic board, it's impossible to verify your conclusions. But, Small Dog Electronics is an Apple authorized service provider, and is protected by Apple's service and repair provisions, as are you, by extension. As long as the replacement was within 90 days, they are obligated to replace your logic board under the terms of the 90 day parts and labor warranty, at no charge. Apple reimburses its dealers and service providers for such events, and provides the replacement logic board at no charge to them.
If, for some reason, you do not wish to return to that outlet for service but your machine remains in that 90 day window, you can take it to any authorized Apple dealer or service provider to deal with: it need not be the same company who initially performed the service under the terms of a warranty, AppleCare extension or a repair authorization extension. You may also simply contact AppleCare representatives at (800) APL CARE to arrange for service again.
If you believe that the service module last placed in your machine was then or is now defective, then you should be prepared to demonstrate that as best you can and as reasonably as you understand the matter with defective to capacitors, to an AppleCare supervisor. It's difficult to believe that an obviously defective board could or would have been used if a center received one from Apple, or that such a board developed this issue within 90 days of receipt. But, if it did in fact do so, the visible evidence is usually quite obvious.
If, however, the board was replaced for some reason outside the terms of its original warranty, any AppleCare coverage extension or applicable repair extension authorization, then your options are limited to returning to Small Dog Electronics. I must tell you that they have been in business for two decades, and have a reputation for resolving such matters amicably. Call and ask to speak to their service manager, and be prepared to outline the fact of your case. You don't provide enough information about the events to know if you're covered, but if standard Apple rules apply and you are, there should be no issue with resolving your current dilemma.