Yes, you can sue the site. Since they do not have a TOS, the "common law" of business transactions will be followed by the courts.
You are probably better off that they do not have a TOS, because they usually limit liability, reserve the jurisdiction, etc.
However, law suits are expensive. How much were your damages? Is it worth a fight? If you win, does the site have the money to pay? Can you go to your local small claims court? You need to have a consultation with an attorney and find the answers to these questions and more.
Andrew M. Jaffe
Attorney at Law
Practice Limited to E-Commerce and Internet Law
This post is provided for general informational purposes only and is not intended to be legal advice specific to you. This general information is not a substitute for the advice of an attorney in your jurisdiction. The attorney client relationship is not established by this post.
Terms of Service means something totally different from whatever premium you received. Terms of Service/Use are not required, and what your damages are is impossible to determine from your facts.
The above is general legal and business analysis. It is not "legal advice" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.