Within the first year of ownership of our van - a different make from yours- we had two problems which were covered under warranty. There was no quibble about the repairs under warranty.
Neither problem affected our use and enjoyment of the van.
Parts for one of the problems came to the dealer from the manufacturer fairly quickly but the other had to come from the original part manufacturer - a window. It took several months.
The van manufacturer was not really interested in supporting an earlier procurement of the part despite the fact that they were still building and shipping the same van so obviously had stock. Spares don't earn them money. As mentioned once they have your money its not their problem anymore but the dealers.
While you may consider it an option to reject the van completely - terms and conditions allowing, there are some things to take into account.
1. You lose use of the van and may have to wait sometime to get another one.
2. Another van may cost you more because of supply and demand and inflation.
3. Another van may still have the same or even different problems so you're back to square one.
4. I can't think of point 4
The dealer was good at communicating but their hands were tied by supply issues. The manufacturer, less so and only communicated when I pushed them, although it had no affect on the outcome.