Overcharged.for one rear lightbulb

I Send my car in to WAckers in Paarden Eiland to change a light bulb. The bill came to R1641.60 The car was sent by Wackers to an auto electrician named AUTO ELECTRIC SOLUTIONS for repairs and Wackers have added on two fees.<br> <br> The first one is R480.00 for a diagnostic check......I ask myself why they would be doing something like this if it is an auto electrical problem. <br> Then they added on a sundries fee for R120.00 . I don't know what that it is for but find it VERY petty. <br> <br> Please can you advise me as to what the next step is As I would like to get the R480.00 plus the R120.00 back.