Stop harassing my mom!!!

I have been paying my mom's medical aid for 3 years during which we used only the Health Saver. I recently lost my job and cancelled the medical aid in the middle of March 2023. Now my mom is being harassed by Health Saver saying she owes them R600 in instalments otherwise they are handing her over to debt collectors. What is wrong with you people? I clearly stated that I don't have a job anymore so I can't afford to pay the medical aid anymore, so obviously that includes the Health Saver account. Why are you demanding instalments for a cancelled policy????????