Disappointing experience at Kia Alberton

I am really extremely disappointed in the service recieved for Kia Alberton. Since I have bought my car I have had an issue with my seat belt, where it unclips. I did mention it to them each time the car has been in for a service, and each time they just cleaned it. I mention to them this year that it poses significant risk to me should I get into a accident my insurance will not pay out. I asked the to order a new part under warranty. It took 3 weeks to arrive, and I booked the car in Yesterday to have it replaced. As the day was ending and still no update has been received I phoned and was told that the part was wrong and the driver had to go back 3 times and brought the same wrong part each time. Phoned in again today and was told that it would take another 3 weeks for them to order the correct part. This is extremely frustrating and the service manager is rude and basically told me that it is my problem. This is horrible after purchase experience.