Hi I ordered my 1.5 d on the 1st July and collected it on the 14th September. To be honest your dealership should have contacted you to keep you up to date with your delivery date. If I were you I would give them a call andvask them to explain the delay.
I ordered mine on the 20th of August it is due at the dealers first week of October. I to have had no updates from my dealer. Not quite in your position, was thinking I may get updates.
Now I'm thinking no news is good news, but I will be making contact at the end of September to make sure everything is ok.