hello Dilemma3000
and welcome from me too
do you have Power of Attorney for Health & Welfare? - I appreciate that strictly it doesn't come into force until the donor no longer has capacity, but it may show the GP that your dad wants you to be involved in all aspects of his health and welfare and so give you a print out of your dad's overall records eg his medication and diagnosis
of course your dad himself has every right to ask for sight/copies of his medical records, so he could ask the GP - might you both visit together to have a chat with the GP and explain what's going on; it would also be a chance to up date the GP on how things are currently for your dad
I don't see why the GP would charge for this - I guess you have to check that with the surgery - though if the GP fills in the form themselves, I guess that's additional to his general duties
I do wonder whether it may be worth considering a move to sheltered and more especially extra care sheltered accommodation if any is available - your dad's condition won't improve and moves can be disorientating (not always) so it may be worth considering
best wishes