Abby, Jess and other such people who I know had cafepress accounts: read here.
If, after reading that, you wish to close your account with them, here is the link: http://www.cafepress.com/cp/members/account/closeaccount.aspx
(nicked from various sources yadda yadda)
Update: http://www.zazzle.com seems to be a possibility to switch to, if you want to find a replacement site to use.
But yes. End your dealings with those people immediately!