Isn't it included in your contract? Usually preparing pink books for new buildings can take even longer! And in most cases, the exact time is stated in the sales and purchase contract. Probably you better hire a translator, someone not connected with the seller, and ask him to translate the whole thing.
Also, make sure the contract includes a paragraph stating that the last 5% of the property price will be paid only after you have received the pink book.
When I was going through the sales and purchase procedure myself, I did hire a translator, but he also was working for the seller, so I didn't feel totally safe. The pink book was issued in 6 months or so, but I also was quite worried and anxious about the whole situation. Thank God now it's okay and I received the owner certificate. Learn from my mistake and better hire some independent professional. Hope this cleared things up))