Samsung S6 software upgrade damaged motherboard

I am highly upset with Vodacom. Took my phone in for repairs after it was explained to them that my phone had software upgrades and that Samsung \hard reboot"the phone they still do another software upgrade. Got a message that I can collect they phone. Collect my phone switch it on as I was told I have 12hours trail with my phone. My phone got so hot in 5 minutes needed to switch it off"