Then that is your issue. Runabouts at this dealer group are reconditioned to MOT standard only and anything outside of this remit is not repaired.
They are called "Runabouts" for a reason - cheap cars to get people on the road. Sold with circa 12 months MOT and a 30 day warranty on the engine/gearbox and that's it.
Did the sales guy explain this?
If he did, then they are doing NOTHING WRONG.