How come all my http URLs are turned to https?

I think you should just get the certificate renewed, and if you need a free one go to letsencrypt.com. A growing number of hosts offer Lets Encrypt certificates as an “easy click” type option on their control panel too.

If you’re real keen on taking down the TLS/SSL functionality, I hope you’ll at least mention that to your client before removing a good part of their websites security all on your own.