Dual citizenship fiasco!

My husband and I are dual Australian and UK citizens and have traveled back to the UK quite a few times to see friends and family. In December we spent $17000 on business class flights to fly to Glasgow probably for the last time as we are both close to eighty years old. In January we found out about this new rule about needing British passports but to start with there was such a lot of misinformation that we thought all we needed was an eta, so we applied for and got it, it cost $402 plus international fees and then of course we had to apply for a refund, which we got, minus the international fee of course. We then had to start the process for British passports and what a delight that has been! Because my old British passport has een lost it had to be canceled first before I could apply for a new one, however I sent in the required documents and have been informed that my passport will be delivered tomorrow so here’s hoping! My husband on the other hand only had an abbreviated birth certificate so he sent away to the UK for a full one, he also had to photocopy every page of his current Australian passport, even the blank ones! Forty pages in all and they say they can’t accept the copy of the birth certificate, they need one that’s printed before the time of his last British passport!!! How will that change anything! He served in the British army, he served his country, but that’s not enough either .He’s now supposed to come up with either medical or tax records from fifty five years ago. They reckon it’s to protect the borders, from who, certainly not illegals! There was absolutely no warning about this, it was just dropped on us, what about people who have to fly home quickly because of illness or death in their family and now they can’t , there should have been a minimum of at least six months warning with adverts everywhere telling us about it, the whole affair has been very badly mismanaged and people are suffering because of it. My husband hasn’t been sleeping and is extremely stressed by the whole thing.