What now Bonitas

I have been a member of a medical aid for 27 years. 11 years with my previous employers inhouse medical aid. I resigned and joined another medical aid in July 2017. I was not happy with them and moved to Bonitas in Jan 2018. Even though I have been a member of a medical aid for 27 years, I was put on a 3 month waiting period. Over the 3 months I paid almost R22 000 towards my subscribtion and I had to pay my own chronic medication. This was fine as I agreed to this. I paid my April fee and my medication was paid for the month. I could not pay from May onwards as both my husband and I am currently unemployed. I was issued with Medication to the value of R1 900. My membership was terminated as at end of may and now I am expected to pay the R1 900 back. My question is, did Bonitas not make enough money from me when I paid my monthly fee and did not claim anything?