Bonitas not covering Diabetes (PMB) treatment in full despite doctor's motivation

My daughter was diagnosed with Type 1 diabetes last year. This is a PMB condition that all medical aids must cover. The cover had been fine until earlier this year, when suddenly they reduced cover so much that we had to start funding part of the monthly expenses ourselves. In particular, instead of covering the cost of 100 needles, they suddenly dropped that to 30. That means you have one needle per day. They say that you should re-use a needle for multiple injections of insulin per day. This goes contrary to all advice received from multiple doctors and nurses. It is a health risk to re-use needles, yet Bonitas recommends it. Even the manufacturer of the needles says that they should not be re-used, since they are not designed for re-use. They are single-use needles. After having the doctor send through a motivation (at our own cost), Bonitas increased the cover to 60 needles, even though the doctor states that we need over 100 needles per month. In fact we need close to 150-180 needles per month for all the injections by now. Since type 1 Diabetes is a PMB, Bonitas is required to cover the related costs, yet they are not doing so, even with motivation from a doctor. If a doctor's motivation is not even enough, what else is there? Sounds like Bonitas is making medical treatment decisions themselves. Really disappointed.