Unwillingness to assist special needs passengers

I booked 3 airline tickets on 29 March 2015, booking reference 208LPN. Two of the passengers require wheelchairs as they are unable to walk to the aircraft. After numerous calls to the Call Centre I ended up speaking to two most unhelpful consultants, Dan and Ashley who both insisted that their company has access to only 2 wheelchairs that have been booked already. They suggested that I changed the booking. This is not possible as arrangements have already been made to pick the passengers up at OR Tambo. Now I am left without any option to get the passengers on the aircraft.<br> <br> The first and the last time that I will use this company!