Wifi connection

I have done 6 tests with wifi manager and upstairs on the 3rd floor where the office is, is a really bad network, I have had contact also with your online chat, but everytime they ask me to do.a test on the 3rd floor I lose connection with the chat and have to start over again, but if I do the test on.the ground floor my connection is good but that doesn't help with the office.  I've been told I can get 2 free wifi plugs please can u tell.me how to do this as when I do.the manager it says sorry we cant make the connection better please contact kpn but nothing about the free plugs, but when I contact kpn they ask me to do the test again even though lose connection everytime please can some help help, if I need to buy the plugs then advice on the best ones as I am.struggeling with my buisness with such a bad connection. Thanks in advance