Core refusing to fix or replace iPad Mini

Last year July we bought an Ipad Mini Retina 128G from incredible connection, recently it stopped charging, after trying various cables with no luck it wad returned to Incredible. They said it would be sent in and the report came saying they found dust particles inside we must have opened it so warranty is void. How may i ask does a person open one of these devices that are sealed **** from the factory? Either someone at Incredible has opened it or someone as Core has stuffed up and are now refusing to fix or replace the defective device. First and last Apple product for me if this is how Incredible/ Core conduct business. The iPad is used for Navigation purposes on an aircraft along with other GPS devices. My wife has an iPhone and an iPad Air which has now gone up for sale as we dont need this kind BS treatment from an Apple reseller as im sure we will get the same treatment. High Disgusted with an 11K paper weight. Karma will come your way and i hope it hits hard.