You should never have to agree to a new contract. This is their way of keeping you locked to them for another term which is mostly 12 or 18 months. What was their reason for asking you to sign up to a new contract?
It was my fault .. the Newfster and one or two others advised me against it at the time, but the terms were already agreed.
I was given a new laptop for Christmas and I wanted to change from the modem to a wireless router. The router we bought wasn't somehow compatible with my PC .. a friend sent me a link regarding an offer that AOL were advertising to new customers.
On the strength of that I ordered a new router and as an existing customer they gave me a deal which meant I didn't have to pay anything for the first three months.