The interview date will depend on your priority date. If your priority date (date your I-140 was received by NVC) is before the cut off date published in Table A of the employment based section of the visa bulletin then NVC will book your interview, if not then you'll have to wait. I am afraid there's no other way, they are very stubborn about it. I asked them directly and received a generic reply with the same wording, which I am sure they send to everyone. Pations is a verture especially more so when there's no other alternative 😀. Keep us posted on the progress please.