Complaint for hyndai plumstead

I have a complaint, I bought the car in December 2017 at hyndai plumstead. All was well sales men was friendly , went to fetch it on the 30th December. He told me that he has ordered a spare key and will send it when it's ready for collection. All was well untill I had to call the sales men reminding him of my number plate. And now it's almost the 6th month since and have not received my spare keys. Told the guy that my front passager's belt does not sense when it's not put on and the car moving and my car computer box was tempered with and the gear stucks when m putting it on reverse. The guy promised to call me again and book the car in , up untill now no one has called. I phoned the sales manager in the 14th to tell him of my story and he promised to get back to me. I am so frustrated by all of this and now regreting me buying the car at Hyundai, I work for financial institute and do Vaf pre approval almost everyday but with the poor experience m having with this company I dnt think I will refer anyone else.