Thank you for your question
My name is Clare and I shall do my best to help you
In fact all you actually need is a Change of Name Deed - not the formal process of a Deed Poll
There are even free websites that help such as the one here
It is very rare for any institution to actually need the formal Deed Poll process to be followed.
If you do decide to follow this route then you can attend your local court who will deal with you for £5.
Please ask if you need further detail
Have they all confirmed that in writing - I ask because in fact you are legally entitled to revert back to your maiden name whenever you wish
I understand - but do the Change of Name deed - the passport office and DVLA will accept that and once you have those the bank has to follow
However in any event a solicitor or barrister is an Officer of the Court - or you can attend the local County court - and the cost will be £%.