Miembro

I did log onto a website 'Down under dates", one evening around 6-7 months ago. At that stage it was advertised as a $5 one month no obligation trial. I never used it again. 3 months later I received an email to say that my account was locked and that I owe them $150. I went back onto the website to pay the $150 and close the account, but the website was locked and said that I needed to now pay $300 to unlock my account before I could close my account? I thought that this looked like a scam and did not pay. A short time later I received an email similar to the one above. I ignored the email. I have since received 2 other emails from them (the above is the 3rd). Do I need to pay anything? I do not believe I do, however I do not want to receive a legitimate bill down the road for a large sum? Also, can the dating website continue to charge $50 a month when I have been locked out and am don't ever use it? I believe that this whole thing is a scam?