After ordering in February suddenly new delivery date and higher price

In February I chose a 850i as a Gran Coupé and signed the contract with my dealer. The dealer told me then that he still has a quota for June / July. As a “customer request” is in the contract precaution the August. Now I asked again if there is anything new in terms of production and then I was informed that because of the model year change the quota had expired and he now has to “pack” a new quota. But this has a delivery g at the earliest in October and also the new prices. In the meantime, the car has increased in the base 3,000 € in the price. Yes, I will read the small print, but the question to you: Is this currently common and are the prices really not fixed? How can it be that a quota simply disappears?