joint account help

[2bornot2b]

hi im new here and i need some help. i made a joint account with my now ex girlfriend because she had bad credit and shes not paying anything when she is the sole person responsable to make payments for the joint account.. we made a contract before we did the joint account stating that im opening the account but she is the only person that can use the account not me and pays what ever charges there is to the account not me. i want to take this a legal matter or if there a way that i can transfer everything to her and not ruin my credit. any advice will be great thanks