Ring says my email address is already in use

I have just bought a Ring doorbell for the first time. I downloaded the app and went to set an account up. It said that email address is already in use. I have never set an account up for this.I reset the password and and accessed the account. The name on the account is someone I have never heard of. There was an iPhone registered to the account today (my own phone) but also an iPhone 4S in 2019. I have never had an iPhone 4S and have never registered an account with Ring before. I tried phoning customer services but they are closed for the day.I have seen other people mention this same problem. Anybody know how big a security risk this is?