No customer service or help

Every time we take our vehicle for a service at Mazda Randburg, we have asked them to check our radio and infotainment system as it randomly dials any number and randomly changes radio stations. While it was still under warranty and they could never find the problem but now out of warranty they find the problem and now want us to pay for it when we have brought up the issue so many times. Even though we have an invoice stating that they reset the radio and it said that as we complained but now, they say they fixed the problem which they never did, and the worst is they have no record of me complaining other times. I lay my life on the line that I did but unfortunately all the good staff gone who knew me and assisted in the past. They are accusing me that I never complained, and I would not lie about this. They say some liquid is split on it so why back in 2022 did they not say that but just reset radio. The Randburg branch manager dismissed me and did not follow up on my query and then came back and said out of warranty when I sent an invoice where they could clearly see that it was under warranty and the manager had the information up front. Mazda SA says under warranty the Randburg branch must deal with it, but they are accusing me of lying and spilling something on the unit. We are looking at buying cars but the way Mazda has treated us although we were looking at Mazda will not be going back to them. Very angry and only now a month later due to Head office contacting Randburg did the manager bother to email me and pass the blame onto us. So Mazda SA have just dismissed the complaint and Randburg Mazda saying as we did not complain and they did fix the problem which they did not they are not doing anything about our complaint which is very unfair and why should we carry a cost for some thing we have been complaining about since 2022