Split wifi

I can guarantee you mine need split my new galaxy tab keeps getting put with the  2.5 and then only get 17 to 36 mbp we pay for 1000 and my sonncan not connect directly to the ethernet with cable thru the  router! Ive had problems for over a year with low speeds its redic. I know its possible we had 1.2 gigs for about 10mins when a new line and router were installed but then it was back to its low speeds by midnight and have not since gone back to the 1.2g. When i aquire about it its a joke to these ppl.. If i can understand what they are saying, and im not talking about the tech.  I understand how this stuff is supposed to work.  They say its all taken care off can you tell me the speed your modem is saying and its always above 1300 id li,e to know who in this house has that casue its not happening.. i have a booster i have not hooked up yet.. I want to connect to the 6 with my tablet and it gives me 2.5 how do i split when the save button is greyed out?  Sorry for the rant im just tired of paying SO MUCH MONEY and not getting what i pay for!