BRP Enrolment help needed

[torres1]

I wonder if anyone could help with on ongoing issue I have with trying to obtain my biometric residency card. Just a brief history of my immigration status, I am Brazilian and I was married in 2006 to a British citizen and was granted Indefinite Leave to Remain in 2010. This was issued in my old passport which was in my previous married name. When I renewed my passport at the Brazilian embassy my new passport was in my new married surname and whenever I travelled I carried two passports as the indefinite leave to remain visa was in my old passport. This never was any problem entering the UK.
In February this year I was suspended from work as the HR department said having checked with the Home Office I didn't have the right to work in the UK without having the ILR visa in a current passport or a Biometric Residence Card. I was absolutely shocked at this but took the necessary steps to ensure  I applied in order to obtain the card.
This is where further trouble began. I applied filling out the form and sent it off with all necessary documentation which included 2 passports, one with the ILR in the old passport and my current passport with my married name in ( I also sent my marriage certificate again).
The Home Office wrote back to me in my old name and I wrote to say that this was not correct as I had filled out a section to inform of a name change during my time in the UK and also my new current passport is in this married name. Despite all of this, the Home Office is refusing to change the name to my new name. The  other problem is I don't have any proof of my old name as all my current documents are in my married name. I therefore cannot register at the Post Office as I have no proof of my old name.
I am at my wits end and at a complete loss as to what I should do. I would really appreciate any advice or help you may offer in how I can resolve this matter. Many thanks.