Thousand Trails review: sew site policy

We have traveled all over the us using tt and other campgrounds. Only at mount vernon/bow do they assign sewer sites. Others are first come/first serve or the lottery system. Both work well. At bow, this is the 3rd time we were assigned a sewer site that was double assigned. The last time was today. We actually were in the assigned site when someone came along with the same assigned site. We were told to move, again, as they were assigned the spot first. This is the 3rd time for this same occurrence. This system needs to be addressed. We were offered a different sewer site a day later which would mean first moving from the non-sewer site to the assigned site, then moving out of the assigned sewer site for another day and then removing to the new assigned sewer site tomorrow. That is unacceptable and a lot to ask when it was not our error. We have cancelled all our future reservations at bow and will call customer service on monday to cancel the remainder of our time here. Change this system.