I would suggest trying the rolling reset, it's free and easy to do with absolutely no negative impact. It is unlikely that it will solve your issue, but hey it's free and if it does work you just saved yourself a buttload of time and money.
Did they by chance bleed the hydraulic system? I know you said they reset it, but if I understand right the system must also be bled properly.
Also if it's the GPS that's gone bad, which can happen, it is a pain to install, but can be done in your driveway, no lift needed. I posted a DIY with pics and everything a while back, it outiines the symptoms pretty well too.