Terrible service from Discovery Health

I have been apart of discovery health for many years and have always maintained my premiums monthly. Now having my second baby I have come to learn that they have reduced the amount of scans they are willing to pay for which is not a problem unless you have gestational diabetes which i have been diagnosed with and you are medically required to have monthly scans to monitor your babies growth due to the condition. I have submitted numerous requests which have been motivated by my doctor and all have been turned down by the medical aid. I cannot for the life of me understand why this is not an acceptable cause for additional cover just for the duration of the pregnancy. What sort of legislation allows this? I think it is really unfair. The minimum two scans would make sense if one had a choice. This is out of my control and am forced to use savings that I no longer have. Terrible service from Discovery. I will be looking to change once I get thru this.