Mercedes Benz Sandton delivering NO service to its customers... Why do we still support these businesses?

Mercedes Benz Sandton is the epitome of how big business does not care about customer service. I have purchased my car from them, serviced it with them for the past 5 years. Just before my car reached 100K, I called MB Sandton on the 17th August 2022 and enquired about my service. I was then asked a couple of questions and then told that my car is only due for service in November or at 104K kms, whichever comes first. I asked the Service Consultant about my service plan and she said this will be the final service under the plan. I took my car in for a service on the 16th November 2022 and my car was received. Only in the afternoon I get a phone call to inform me that my car is out of service plan and I would have to pay for the service. I spoke to Vernon and told him that I was advised by their Service Consultant and now they changed their story. I was made out to be a ****. And so I spoke to Koos and Marco. And I was still made out to be a ****. I then requested the voice recording of the phone call which I made in August 2022 on the 16th November already. Today is the 28th and still no voice recording. I have said it on record that I am willing to pay for the service if I am wrong and that was not the conversation which took place in August. However, I believe that they are not willing to assist me. I have been sent from pillar to post, even **** to about who the dealer principle is. I was told it is Alex and now today I am told it is Jaco. Again, can you just have integrity in the way you do business? Why does it take so long just to get a recording? And in the meantime I must find my own way as they are not willing to assist me. I will make sure everybody that I know gets told about your horrible service. I will NEVER EVER purchase a car from you again!