Fedhealth makes double deductions and don't reply to emails

I recently joined Fedhealth because I started working for myself and had to leave the group medical aid I was previously a member of. After I joined, in the first month, they did not deduct my premium on the agreed date of the 5th, and no explanation was received. The following month, they tried to deduct double the premium without any communication or warning. I only had enough money in my account for one month's premium since I am self-employed and cash is limited. They sent me an email advising me to set up a direct debit, so I responded with an angry email asking what was happening. No reply was received. Shortly afterwards, my cover was suspended. I tried calling and waited ten minutes for an agent, but I hung up because my airtime is limited. I then withdrew money from my savings and made a direct deposit. When I ordered my medication from the pharmacy, they informed me that my medical aid would not cover any of it. I contacted their online agent and was connected to a very friendly and helpful representative—honestly, not being sarcastic. He managed to calm me down and helped lift the suspension so I could get my medication. By the third month, on the 5th, another double deduction occurred. Why? No one knows. I immediately emailed customer service, but three days later, I only received the automated reply. Today, I got an email stating that my bank rejected their debit order. I am frustrated. How hard can it be to resolve the original issue? Each time, I have to pay bank fees for a rejected debit order, which also negatively affects my credit record. Please help me sort this out.