This appears to be one of those scams that automatically subscribes you to a service you don't even know about. In my case the subscription was to Madfun.mobi. The subscription appears to have been initiated from a Tablet which is not used as a phone, therefore messages are not checked regularly. The first time I became aware of the charge was when I received a charge on my phone bill. (I had been using this Tablet as a WiFi Hotspot during the month when the subscription started. Not sure if this is relevant, but a previous comment suggests that maybe it is)

2 x SMS on my modem suggesting that my next telstra bill shall be docked $6.99

this comes from hotspotting from your phone. just had it happen to me. somehow a dubious website is able to determine the mobile phone number and send the text. lucky i am on pre paid so they cant scam me of money.

I am trying to work out how the hotspot like lets this happen.

Text saying subscribed to funny vid
$6.00/ mth
Dont know where from