Macbook pro (13-inch,2018,4TBT3)Rear shell bulge

Hello:

I am customer of apple from Shanghai ,China.I have the iphone and ipad too. So I am a fan of Apple.I think the apple is Apple stands for quality and beauty. Recently I was a little disappointed with Apple

I have bought a Macbook pro (13-inch,2018,4TBT3) on 18th,September.

The Serial No.is C0***HCF.

I find there is a problem on back shell of my Macbook pro.I got to app store in Shanghai,but they said it is bend by extrusion. Replace the back shell, you need to pay an additional RMB 1,200, which is the value of nearly 10% of the computer

I doubt their identification.

1. The Macbook pro have never bent or fall from I get it. It is alway in a bag with protection when I take it to our office or home every day.

2.The Apple store staff said the Aluminum shell is easy to extrusion by little bend power.However the shell is made of Aluminum sheet.it must be stronger than plastice sheet. so why it is so easy to extrusion?

I buy a new computer,but I have to pay RMB1200 to replace the back shell,so I think it is impossiable.

And as the staff explaination,the shell maybe extrusion in the furture, How can I trust the high quality of Apple?

I buy so expensive computer, but its quality can't be guaranteed.

Can you tell me how can I do next time?

The following are the images.

I am looking forward to hearing from yours.

Thanks so much.

Wei