Safe National of America Problem with Wifi Signal St. Petersburg, Florida

I bought a Wi-Fi router from Safe National of America. I bought it since I wanted to have internet access in any part of my house and the range of the router I bought was quite big and Safe assured me that the router is a good one. When I arrived home that day I got very busy with work so I didn’t have time to check it until the following evening. So excitedly I set the router up in my living room and got great signal on my laptop. But when I transferred to my room to continue my work there, my lap top cannot get any more signal. I thought it was my lap top so I checked it my PDA and the same thing happened, I can’t get any WI-fi signal other than at the living room and the kitchen! I called Safe the following day and they promised me that they would send a technician to solve the problem, and the technician arrived a week after and it would be more if I hadn’t badger them by calling everyday! We have to make a great effort before this company will do their job right!