assessments

I am in an HOA in Kansas and I have a problem with assessments and House Bill 2472. Our HOA has had it's own covenants and bylaws since 1972. They state, that assessments should be paid, a certain amount per member, once a year. My parents and my wife's folks have all moved into the same HOA. They all moved here because they are on a fixed income and the dues were so inexpensive. Now, since HB2472,the HOA is trying to charge them by the lot instead of by the member saying that 2472 supersedes any bylaw or covenant. This will take my folk's dues from $60.00 to over $1000.00 a year. I know that sounds cheap, but it is a rural HOA. My question is, are we grandfathered in to our old dues (by the member), or can they change (without vote)to charging by the lot. When my parents bought their property, there were 17 lots and one title. Even if the HOA gets by with charging by the unit (lot), there should only be a one unit charge because they didn't have a choice, it all came as one unit? I'm I right? A unit can be more than one lot(like a family unit).

Thanks for the help,

Will