Bad customer service Constantia Kloof

There is just no customer care or service at Mercedes Benz. There is just a blank refusal to contact me and I left a-lot of messages, who can I talk to to get my issue resolved? My ML63 ignition switch was repaired by Constantia Kloof Mercedes in September/October 2021 since then my SRS and AIRMATiC is not working. They drove my car with a broken V-belt to get it repaired across the road from the dealership where they “apparently” have more work workbays. I have left 5 messages and send email for Jaco Boshoff and there is no reply. They were quick to get my details when I complaint on twitter but NO feedback NO call