OmniServ or OmniShambles as they have often been referred to, provide the WheelChair service at LHR if I'm not mistaken.
Just to provide some context as to how far BA are from involvement, I walked into the CCR last week and there was a huge row going on.
The Reception lady, was being berated by the son of a Prem, who had ordered a wheelchair. The wheelchair hadnt turned up, and the BA staff member was frantically calling all the numbers she could find; including the Duty Manager (who came along a few minutes later). Now, if BA cannot guarantee wheelchair for one of their absolute top customers, what hope is there for the rest of us!
M