At one time we were C to C members and had two separate home parks, one in Colona Colorado and one west of Gunnison Colorado. While I never had any problems with the national C to C organization, the local parks around the country did try to play games with us on many occasions, such as you have found.
We found many of the C to C campgrounds worked at discouraging us from staying. Often when we asked for a week, we were told they could only give us one night, but come back in the morning between some hours to check again for the next night. These parks often had numerous sites available for every night we were there. Most/many also tried to sell us a membership in "their" campground, which is apparently where they make much of their money.
We were given the membership in the Blue Mesa C to C by my wife's aunt, which turned out to be the most expensive gift we ever received. LOL It is a nice campground but we didn't stay there enough to justify paying the $450 a year home park fee to them.
After about 3 years of being in C to C, we dropped out with them. Lucky for us, our contract allowed that, if we were paid up with our home park. They have some nice C to C parks, but also many questionable ones, IMHO. Many we stopped at were mainly trailer parks and they might have a half dozen RV sites, somewhere in the park. Many of the parks that tried to sell us a membership in their park, would mention how we could stay in some very nice parks, not their's, for a very low nightly fee, so long as we paid them their home park fee.
For some RVers that use the C to C system enough, if works well and they get their moneys worth, they feel. Others like us, didn't feel it was a workable system with the way we like to travel and overnight at campgrounds. Many were way off the beaten path of where we were headed.
