Is your rig still on the side of the road after 2 weeks? I think not. I believe you were towed to a repair facility (as the service contract requires). I believe you also don't like that facility, but that is not really Good Sam's problem. Kind of like having an HMO and you want to use a doctor outside that HMO. That is going to cost you.
What is the hold up on your repairs? Is it parts, is it the shop is backed up, is it the repairs are just going to take a long, long time, or is it truly incompetence? Maybe, Maybe, Maybe you can convince Good Sam to tow it to another location if you can prove to them the shop is purely at fault. But if it is only they aren't as fast as you think they should be, that probably isn't going to get you satisfaction. And on top of that, you are going to owe the shop for what they have done. There probably isn't any way around that. Good Sam probably can't expedite parts, can't make a 6 week repair take 6 hours and can't move you to the front of the line at a facility they do not own.
Repairs on RVs can be very, very frustrating since they are pretty close to custom built compared to cars and trucks. Everything takes longer and parts often need to be special ordered or even fabricated. Just be sure you are blaming the right culprit.