We Buy Cars Frustrations

I have purchased a vehicle on the 20 June 2024 Cash from We Buy Cras Dome and have yet to receive the NATIS documents. We phone on a weekly basis with no real feedback. They can't tell us where it is for us to collect and has also offered to send it via Courier, which never arrived. They also can't give a reference number for our calls, which means we have to start over every time we call. The salesperson has also made promises which was not kept, and now don't take our calls any longer. I also have to present these documents for insurance purposes, and also if I want to crossover the border, or renew my license. I don't know what to do anymore?? It has been almost 4 months!!