Review on Swann BNC Coaxial Cable for Security Camera CCTV System - UL Certified, Fire Resistant, 100ft by Johnny Burns

I bought a 6 channel Swann system and Swann said I could extend the cameras up to 300ft. The system comes with 60ft cables and I only need 75 more feet so I bought two 100ft cables. None of the cables worked properly (the video keeps cutting out). I contacted Swann and they replied that "the cameras only work with the included 60ft cable. I asked why they sell 50ft and 100ft extension cords and why the tech said they would work up to 300ft but there was no future response from Swann! Revain should look into this as I have purchased cables from them in good faith