transferring isa monies

sharkmeat

i am new to this,so i hope i can get some info on this problem!!
to start with my father in law died in 2006,in his will he left certain bequests to various people,but the bulk of his estate to mother in law including an isa with the a & l.
my wife and i were made executors,so we have followed all proceedours as req.
unfortunately my mother in law was diagnosed with severe dementia and we had to apply to the court of protection for the right to handle her affairs etc.
we were granted receivership and notified all relevant parties to this including the a & l where all my father in laws and mother in laws accounts were with.
we have had no problem up til now,my wife is on my mother in laws current account as receiver and has been issued with a credit/debit card for this account to pay or receive monies for my mother in law.
the problem now is that the a & l have been very obstruction as regards the isa account,we want the money in that account paid to my mother in law and placed in her current account as she now requires it, because of care home costs,and then close this isa
the A & l have so far been very relunctant in carrying out our instructions,even after being shown the certificate from the court of protection and a copy of my late father in laws will.
their own legal dept has recognised us as being allowed to handle my mother in laws affairs and we last wrote to them at narborough on 30th april giving them 14 days to comply with our request.
to date we have not had a reply or any notification of receipt or how they are handling this.
this has been going on now for 12months and need some advice on the next steps to take to force them to release this money to my mother in law.