Guess how much to change a globe?

After sending the car for 2 services at this branch and got exellant service,i went back to have a globe changed.I bought it at the branch for R78 and asked for assisstance to install it. I was then told by a Mr Ronny that it would cost R300 labour to fit it.This car is still under guarantee and i didnt want to try fitting it myself,because i did not want to break anything and the handbook says to contact the dealer for assistance. Mr Ronny did not explain any company policy to me,and any normal person will not pay that amount to have a globe changed. Why do these people offer a lift to you when you drop off your car for a service,but charge you R300 to have a globe changed!