I think they have many documents that we
assume they don't. Do you have any copy certified or non-certified for those
documents. You might also have some correspondence with a reference number from
home office. Use every effort to find your old documents. I am just writing my
ideas and you might already have done this but if you missed my brain storming
might help. I have not gone similar process to yours but they stamp ILR on my
passport and sent me a letter also and that letter helped me to get into the
country last time I visited USA because I did not have stamp in my new passport
but I also had my old Passport with the ILR stamp. Things can get pretty
complicated and you will get help depending on whom you talk to in the home
office and what mood they are in.
Your best source is Home office and you should immediately call or write them
about the date mix up on your passport. Ask them what is your course of action
should be. If they have a reference on you they probably have complete history
on you also. You should do everything possible from your side like if you had
travel documents or any document from home office use that as the reference and
use your dates to write to home office. If you apply somewhere and you can get
the documents or copies from there that might help too.
Good Luck and sorry couldn?t help you much