Is it legal for a car insurance company to issue a policy without my authorization?

I called a few insurance companies for auto quotes. I went with one company and a few months later reicieved a bill from one of the other companies that i got a quote from. I called them to ask why the policy was issued. The answer was that there "system" automatically issues a policy if the information is left in there for a certain amount of time. I never signed anything or gave any other kind of authorization. Now I have been sent to collections for car insurance I never new I had. Is this legal?