Advice on dealership dispute - what is reasonable?

Hi,
I am seeking some advice regarding a vehicle dispute between myself and an independent second-hand dealership.
I purchased a 59plate 1 series BMW @ 43,000miles in July and in September I noticed an issue with the rear brake pads which I raised with the dealership. More issues became apparent and I am now in dispute with the dealership over reclaiming costs for the repair works. The dealership is claiming the issues are all wear and tear items, so I am looking for some reassurance on whether experts would consider it reasonable for the dealership to sell me the car in the following condition.
Rear brake pads wearing unevenly and worn - driver’s side down to the metal. On board computer never flagged it as sensor wire had worn through.
Front and rear discs all at the minimum recommended thickness:-
Front discs 20.4 mm (minimum 20.4mm)
Rear discs 8.5 mm (minimum 8.4mm)

I am basically wondering whether:

a) It is reasonable to sell a vehicle with worn brake pads and brake discs at the minimum thickness?
b) Could the above issues reasonably be classed as wear and tear as I had the car for 65 days and did approximately 2,000miles before the issues became apparent to me?
c) Are there any services or independent vehicle consultants who will look at all my information and provide written confirmation on whether the car was sold to me in a reasonable and satisfactory condition?

Any assistance would be much appreciated. I have photos of the brake pads and can provide further details of the caliper issues etc. if you so require.

Thanks

John