Life's Grief!!

I am highly dissatisfied with my LG G5 phone. I have had it for a year. End of December, it started rebooting by itself. I took it in to Xecutronix on 12 January 2018 for the 'bootloop' issue as explained to me. I received it back with a main board replacement on 23 January. On 25 January, it started with its nonsense once again, and I took it back to Xecutronix. I got my phone back 13 February with a main board replacement. Needless to say, I have had to take it in again on Monday 5 March, for doing the exact same thing. I expressed my complete dissatisfaction to Xecutronix, and stated that best they keep me updated as to the status of my phone. YET to receive a phonecall from Amos. Never in my whole life have I had the dissatisfaction of owning a phone. Not only this, but I have wasted my airtime for continuous follow up due to complete lack of communication. And the fact that I am paying for a phone which I have had the pleasure of using maybe 3 weeks this year! This is my first LG. Un-freaking-believable! Please advise escalation process of this? Frankly, I would be very insistent on getting a brand new phone, in original packaging, because maybe THEN I will know that being a new phone, it may actually work. As opposed to putting faulty parts back into my phone.