Where to complain

Hi everyone,

I purchased a new Q5 Hybrid TFSI e 55, its a really nice car and I like it, but, when I started to look at buying one I found that the online build my audi was so complicated that I decided to go to my local dealer - local for me is here in Sweden.

After talking with the salesman for some time and finally asking him "do we have all the safety features that we need" to which he replied "yes" my wife and I ordered the car. After waiting many months it arrived. It was only after a few days that I became aware that we did not have the Side Assist which we had on our previous Q5. I contacted Audi Sweden to explain the situation and to ask about a retro fit. No way, impossible, they say.  It's not, I replied stating that there are some retrofitters that can do it, so why can't Audi.  The Audi customer services now refuse to answer my emails and requests for an explanation. So my question to you guys is, where else can I write to, because I feel that when I went to the dealer asking for help to order the car, he should have gone through the list of safety features, including the side assist to which he freely admits that we didn't talk about it. I would then have chosen the Side Assist.  

I have not been asking Audi to fit it for free, I just thought they would have been more helpful in solving the issue, but apparently not, so if you guys have any suggestions I'd be grateful to hear about them.