Reasonable callout fee Ridiculous Price without quoting first

They charge a very reasonable call out fee (R295) to overcharge you without quoting you. They charged me R 6745 to open a treley door. I could have replaced the whole door for that price. They say they can't tell you how much it will be until they see what must be done (understandable), but then just go ahead and do the work without giving a quote. Even if they said the cost would be half of what they charged me after complaining (R4595) I would not have done it. Even at that price I could have fitted a new security door.