It does sound like your NC club set the rules with more than the newbie's best interests in mind.

If it is a situation of instructor-student on buddie box, you don't even need a "trainer" plane to teach. As a matter of fact, starting with a flat bottom wing with gobs of dihedral is actually a hinderance to learning how an aircraft responds to the basic flight controls.

IMHO, as long as you have an instructor on buddie box, a light wing loading sport plane (e.g. Stik or 4*s) is a preferable teaching tool. Heck, my two Stik type airplanes both have lower wing loading and can fly slower than most of the so-called trainers. Unlike trainers, they don't climb and dip with throttle changes, and they don't fight you on the turns. If you learn to fly a trainer with all that "self-correcting" tendencies, you'll have to relearn how to fly most of the other planes that go where you point it.

I think you'll learn very well with a flat-bottom trainer, but you shouldn't be forced to start with one.