I wouldn't let UHaul touch my vehicle. I have had TOO MANY bad experiences with them...I would haul my junk across the county and drive back empty ten times before I rented anything from them again.
UHaul is also typically overpriced...you could have bought a hitch from eTrailer.com likely for less money and free shipping, and did the install yourself. You're going to end up doing your own install anyway at this point.