Bonitas suddenly want me to pay shortfalls

I wrote a review last month complaining about this medical aid . They just acknowledged the complain and promised to call me. To this date I have never received any call from you or momentum. Why suddenly must I have a shortfall of R4500 for every oncoloy appointment? This never happened while Bonitas was still under medscheme. You are deducting almost R6000 every month from me. Where the hell must I get an extra R4500 from? Please pay asap....