LSAT Test Date Change

I have decided to push my August LSAT date to October but can not figure out how to do it! The deadline is August 21st, so I emailed the LSAC 3 days ago but they haven't yet gotten back to me and as I live in Canada, I'm avoiding calling as long as possible so I don't have to pay international rates. When I go onto my LSAC account it says I am registered for the August one but it says I am not eligible to withdraw. Also under the general forms section where there is a test date change form, its from 2018 so that's not much help! I also don't have an email from the LSAC that had the option to obtain a coupon instead of writing the flex.

If anyone has any advice on how to change my date that would be much appreciated!