This is how I do it: Wait for phone to connect. Press the media button and then BT-audio. Then play music from my phone, making sure the volume on my phone is turned up adequately. Sometimes I have to press BT audio again for it to start coming through the speakers.
Some people locate the module in the dash end panel with the fuse box, be sure to check there too. A lot of people now have access to App based diagnostics, it is possible a previous owner enabled Bluetooth in the hope it would work (hence the listing in the on-screen menu) but didn't install the module and microphone.you can programme the central locking part of the key with vcds, which you could pick up second hand, but you'll need to go to main steeler for the top part of the key ie the blade and the transponder . some independent key places maybe able to cut you a key and programme it, but they would need to have the expensive equipment that skoda/ vw Just in case anyone has had a similar issue. My phone would disconnect from the Octavia's Bluetooth whenever I tried to make a call. I have since turned off "Media audio" in the Bluetooth connection on the phone. It has not happened since (fingers crossed!) jAQr.