My website was pointing to a strange IP address

The IP address your domain name points to is something you have to change at your DNS provider. When I do a dig lookup on your domain, I see that it in fact has an A record that points to 31.22.4.50. That’s something you’ll have to get rid of in the domain name’s DNS settings yourself. There is nothing that InfinityFree (or iFastNet for that matter) can do. Your domain registrar’s customer service might be able to help though, if you’re not sure how to remove the record, or are having trouble doing so.