They actively discriminate against disabled parents by refusing to take the most simple steps to accommodate a disability. They don't even deny discriminating, they just claim they are allowed to. They simply state "If our [discriminatory] policies are not something that your family can adhere to then we will refund your card". The same logic would apply to racial, veteran-status, sex based, age based or any other types of discrimination if they feel like it.
My kids love taking gymnastic classes here over the years. They always has lots of fun and enjoyed birthday parties here too.