Rude technician and poor service.

I handed my Asus Vivobook in at Herm**** Computer Mania, Whalcoast Mall. It is still under it's 3 year warranty. I explained that I have been struggling to switch it on, frozen screen and font/app icons sizes change. The problems where becoming more frequent and I could not rely on it for work. Vincent inspected the laptop and described on the job card that the laptop showed "Light damage on the corners, fan/grill broken. N. R Marks". Gave me a copy and said not to worry much about the description on the document. I signed it. This was Friday 22 May. The laptop was sent to head office on Monday. Wednesday I received a mail to say the laptop is on its way back to Herm****. I phoned Wednesday, Thursday and eventually when I phoned again Friday pm, I was asked "Has no one let you know the laptop arrived?" When I picked it up there was written boldy on the package "WARRANTY VOID". No work had been done to fix the laptop and was sent back with no explanation why the warranty was voided. The shop assistants could not explain it either , but said their main technician Christopher did the inspection. I asked to phone him. He was down right rude and unprofessional, saying that I had dropped the laptop. I have never dropped the machine and the light damage on corners is simply ware and tare due to taking it in and out of its bag. He said he knows what he sees and the warranty is void due to damage I incurred. I asked whether the laptop was opened up when he did the inspection and he said:" No, I didn't have to because I know what I see!". When I said I will take this further he said "Be my guest". Gave the phone to his superior, Colin. Colin was much calmer and much more professional. He said the laptop can be sent back and that he will personally inspect it upon arrival back at head office. I am disgusted in the way the matter was handled, no communication to me during the week, explanation as to why the warranty was voided as well as the down right rude and condescending way Christopher spoke to me. I am now without my work laptop for a second week and NOT impressed by the way the matter was handled.