Premier speed

So, I have premier internet which is supposedly (up to 100 mb/s). Can someone on here explain to me why I have never gone above 25 mb/s. My connection lags so bad at times that streaming movies just stops. Or sometimes the connection just drops in general. Of course I've been on the phone with tech support and they want to blame the router. Wrong! Plugged straight into the modem and still only 25 mb/s. Don't even get me started if it's raining out there. 

 I guess I'm just seeing if anyone else is fed up with the blame game.