How do i stop the subscription? I have a test saying that i can do this by texting stop to 61973 - will this charge me more?

Type in kilo mobile on google and you will find dozens of complaints like ours.
Below is a response from David In Cambridge.

Hi, it appears I also subscribed to KKO Mobile service, without knowing anything about it. I received a text on 23 Sep, from
KKOMobile, saying I had subscribed (while driving to work!). I thought it was spam just trying to get hold of "real" people, so
Ignored it - but did call the payforit number (08458341119) from a landline and unsubscribe. Still got charged £4.50 though, but only found out on checking my october bill online yesterday. BTW I am with 3 mobile. I then sent "Stop" text to the KKOMobile number - 61973. Emailed KKO, and had a reply this morning - saying more or less tough luck, we have charged you.
They maintain someone subscribed, and the email infers it could be a child (it often happens). Looking at their terms and conditions, condition 2 says
'The subscriber must be over 18, and have the permission of the billpayer to use this service'.
It could be that my four year old subscribed (playing angry birds...) but he certainly isn't over 18, and can't read to boot!
I have filed a complaint with phonepayplus, in the hope this will be sorted. Pity someone can't launch an action on their website.

I hope this helps