If you don't want to have one look elsewhere.
The 18 month contract doesn't commit you to use the service of course - it just commits you to pay for it. If I got tied into a contract I wanted out of I would seriously abuse the service. That's exactly what I did when I wanted out of UKOnline 3 months early because their IWF filter was breaking access to other services. They wouldn't oblige so I ran a crawler for
http://www.majestic12.co.uk/ 24x7 at over 3TB a month for the final 3 months. They didn't bat an eyelid - now that was an unlimited connection.