iPhone 6 horrible WIFI issues.. 8.2

Hey all

I bought an iPhone 6 3 days ago and I'm having issues with it.. I did everything that needed and set up my wifi. But it barely gives me results. I have 2 bars most of the time but I can't browse or update social media feeds.. my modem is in my living room and I'm in my own bedroom and it doesn't work or maybe once in 4 hours it slowly works. My Samsung S4 didn't have this problem, neither does my laptop, android tablet or even PS4.

I updated to 8.2 and it didn't help at all, I did the reset network settings stuff a couple of times with no results, I even factory setting reset it but no results. Tried 2.4 and 5 GHZ on my modem, didn't work. WPA2, AES, WPA1, reset modem, ... nothing helps.

This is a 700 euro phone.. why is it so difficult to have a decent wifi connection 4 meters from the **** modem..

Please help me, it ruined my weekend and midweek.