Poor attitude and customer service-Arrogance

I purchased a power bank which didn't work. I took the device to request that they test it but the lady became arrogant towards me. I enquired if she worked there and for details of the owner.She retorted saying 'we sell tons of this and this is the first complaint. I'm the damn ****** owner'.After testing the device it failed to work. I took the product and left the shop after enquiring from her staff her name and shop details.