Phone overheating

I bought a Huawei P8 from Vodacom on contract at the Vodacom shop Kolonade the phone started overheating after a while, it was taken back to them this was went missing (******) at the store whereby they replaced it. This phone also started overheating and again taken back to them. They then said they will send it to Vodacom tech dept, after a month got it back and told there is nothing wrong now it overheated again in such a way that the bent cracked the screen!!!!!!!!!!!!!!!!!!!!!!!!!! After some research its found that this is a problem of this make and VODACOM said there is nothing wrong!!!!!!!!!!!!!!!!!.