How long should it take to R&R a transmission

I have a Damon Intruder 34 FT class A and doe's anyone know how long it should take to remove the trans and then install it> Is there a flat rate book on that. The repair shop is saying they have 14 and a half hours on it and are still aren't done. I think it shouldn't take much more that two hours. The trans is easy to get to not like you have to pull the engine. I don't have the space to do the job but if I did I could do it in two hours. I have replaced the clutch in my Datsun pickup in under two hours and it is a lot harder to get to the bolts. It didn't take three hours to R&R the auto transmission in my 89 Corvette and it is real hard to get to it you have to pull a lot of other parts just to get to it.