This is exactly the same that happened with my order for an Astra SRi ST.
I placed my order first week in August last year (2020) and the delivery date kept going back and back. Motability also told me the dealership had placed a new order and the dealership’s excuse was model updates. The Astra eventually arrived in May this year with what I felt were a large number of ‘downgrades’, even including the omission of parking sensors. When I went to collect the Astra, it was under a cover and I stupidly signed for it before realising there were so many ‘downgrades’.
Getting to the point, after complaining to Motability, they allowed me a free exchange and the Astra went back to Vauxhall and I went to a different manufacturer. I will never go back to the dealership or Vauxhall again.