Unstable internet connection?

[Hakki]

I live in Belgium and my internet provider is Telenet, which you probably won't know.
I got a router from them when they first installed wifi. I should be getting 120 mbps, that's what i am paying for, but i am only getting 45 mbps via wifi and 85 mbps via cable? Sometimes it's really fast and sometimes really slow? When i play FIFA 14 in the livingroom, it doesnt lag. But when i play in the kitchen (3 meters away from livingroom) it lags. I've even called Telenet and got a second router , but it's still the same. what can i do.

[LifeInvader]

I'm also a Telenet customer (ook een Belg dus) and all is fine here: http://www.speedtest.net/my-result/3340059977

Perhaps you live in a city (more users = slower speeds) and maybe there's a lot of interference in your house that's messing with your wifi?