Day light ******* by a brand I trusted!

I am highly disappointed at Kia Roodepoort and will never use that branch again, infact I'm reconsidering the brand as a whole! My gear linkage broke as I was driving on the freeway and I then took the car in to have the linkage replaced. The cost was quite hefty but I was told that it was due to it being a big job because they needed to remove the entire front part of the car. It was fixed but on the day I picked it up I realised that nothing on my steering wheel was functioning and my radio was jumping and then would just switch off, things that never happened before I took the car in. I called them and told them what was happening and was told to bring it back to get checked. About a week or two later I went back and I was first told they couldn't fix it that day because they were fully booked, this after I called alerting them that I would be taking time off from work to come have it fixed even though it was an inconveniece as I live in the North of Johannesburg and I was needed at work. Eventually it was fixed and life continued... for about a week until my radio switched off entirely. I called them again and was told that well, I just needed to bring it in again (mind you using my petrol and on my time). I went back as I was due for my service as well and was told by a manager, Mannie, that they would not fix my radio on their account because they had found a coin in the radio and I was therefore liable and how kids must have slotted in there. I'm livid! I feel ****med by these people! If there indeed was a coin stuck there the only people who would have put it there were the people who fixed the car. I never had these issues until then, how come? The amount honestly isn't even the biggest issue, its about the principle. If I knew it was not from what they had done on my car I would accept it and pay for it but I know that problems only arose after that fateful day and if that's how they operate then I will never be using their services again!