Pathetic customer service

On the 9 November I went to the above store on the Bluff I took my laptop for reviewing the salesman advised that it would cost R450 to check what's wrong with it. An invoice was given with no amount just my details, on the 12th went with the R450 to collect a different gentleman claiming to be the manager told me that the cost is now R750. This is absolutely terrible service no price on invoice so you guys just charge people anything url want to. Pathetic service never would recommend anyone to go here. As for their 30 day policy makes absolutely no sense. I expect some feedback regarding this matter.