iStore disappoints

I booked in my laptop at iStore so they could give me a comprehensive damage report. I was charged R600 for this. They have now fed back and said that they were not able to asses the laptop because it’s an old model and the no longer assess those models. I wonder, why then charge the full R600 if you knew it was an older model from the get go, which one can ascertain by the serial number.

Why not advise of this issue upfront, as opposed to taking the R600 and advising you cannot assess it thereafter?