Sony Bravia TV (2015) and Satellite

[Klinks]

Hi all, I've recently moved to a new house which doesn't have an aerial available, but does have an old Sky satellite dish with 2 coax cables running into the living room. I've been told that I can connect these two cables directly into my TV and watch the available channels under Satellite section of the TV. So far I'm not having much luck achieving this. Whilst I was aware that the scanned channels wouldn't be in any form of order, when I'm performing the scans a lot of channels are missing for example: Channel5, Film4, ITV4, etc. And I've now got to the point where I'm really not sure what to do next. On when screen, after scanning the channels and some are available, one of the mode selection screens saids that no sign could be detected for the MAIN and SUB tuner, even I had BBC 1 HD on the screen. The TV that I have is KD-55X8509C which doesn't have the FreeSat app available. I don't know if the satellite is causing the problem, if the cables aren't working properly, the TV isn't up to scratch or if something else is behind the problem. I'm tempted to possibly purchase a FreeSat box, but concerned the problem will still remain. Does anyone have any advice what to do here? Many thanks.