Spam users registering thru HikaShop

We are getting users added to Hika and Joomla without purchasing. We have registration turned off. We believe they are being generated through HikaShop. It doesn't appear that there is a security issue only it creates many fake accounts in our database. Is there anyway to prevent this?

Hi,
I think that the best way to prevent this would be to use the recaptcha plugin.
Hope this will help you.