Rainmaker

Hi Eleanor, it looks like you might have created the 'package' as a separate appointment type? What you should do is create using the Packages option in Acuity - here's a guide: https://help.acuityscheduling.com/hc/en-us/articles/16676883484813-Creating-packages-gift-certificates-and-subscriptions#01FQHRTXAFA8H9C1YFC8FNX1SA
When you do this, you can add any price you like - so in your case you could price it for what 4 sessions would cost (I assume the $396), and then when selecting the appointments that can be redeemed in this package, make sure that you have allowed for 5 so they get one free.
You can also set an expiry date and when people purchase, they'll automatically receive a code to redeem their remaining sessions (it sounds like you may be manually emailing a discount code currently?

I checked your site, and it looks fine. See the screenshots below.