Anyone work with ABN-AMRO before?

Has anyone worked with Abn - Amro mortgage before? I am so frustrated with them. I have submitted the whole short sale packet to them more than 30 days ago and still have not heard anything back as to if they will accept my offer or not. I called to get an update and they said that it is still in processing and the investors have not made up their minds yet. A BPO has come out almost a month ago. I don’t understand what the hold up is. This is my first short sale, I have a buyer ready to go as soon as I can get an approval but she may back out if they don’t give me an answer soon. Can anyone tell me what I should do next? Thanks so much.