Chased away by staff for working in the restaurant.

I am not happy with the service I received from the staff!! The City of Ekurhuleni has reported power outages in the area. So I decided to go to this McDonald's @ Sky City to have a cup of coffee and use one of their open spaces to do my work. I ask the staff if I could and they said yes. After some time the staff approach me and say I can't work from the restaurant. I find this totally unacceptable and unfair. Why can't they accommodate me, knowing that we have electricity issues in the area? This is so wrong on many levels, as a loyal customer, I feel I have been mistreated and deserve an apology!!!!