From my own experience, I would say be persistent, don’t give up and try not to lose your temper – the ball is massively in their court and they have to want to help you!!
I fly tomorrow and submitted my original application in March. I hadn’t heard anything and decided to visit the London office yesterday and join the queue as a last resort. There was a lady from HMPO handing out enquiry forms so I mentioned I was within 48hours of travel and she asked for proof and then took me to the front and handed me a ticket and sent me to the first floor. I spoke to the desk there who said they have added a note to my file and someone will call back – I was called back within the hour and have collected my passport this morning.
I would say if you’re within 48hours and can get down to your local office and speak to someone in person, it might be worth it! Lots of people in the queue were not within 48hours and were being turned away at the door which makes the whole thing so much longer!! My local MP’s office also called on my behalf which may have also helped my case.
This forum has been so helpful and there are so many people in the same position as us and I did see quite a few successful people yesterday.
Wishing you all the best of luck!!