Very difficult scam

I've been charged £4.50 every week for this website funvids, I didn't even press anything, I just opened it, and somehow it got my phone number and has been charging me on my phone bill weekly, what can I do? Or can smarty block 3rd party payments? I've tried messaging 'STOP' to their shortcode 65065, but it said I have insufficient funds, so I bought a £5 bolt on that said it could message shortcodes, I converted it to credit, sent the message again, and it still didn't work, so I don't know what to do