There are a few ways you can tackle abandoned checkout:
1) If your HikaShop is configured so that an order is created before they abandon (which sounds like what you described, because you mentioned "cancelled orders") then you can use the AcyMailing abandoned cart integration to send them an email.
www.acyba.com/acymailing/388-automatic-r...s-with-hikashop.html
Note that unlike the rest of the options listed below, this AcyMailing solution ONLY works if an order has already been created and then is not paid.
2) You could implement an exit intent popup. When the user goes to leave without completing checkout, you can have a popup that encourages them to reach out to you for assistance or to answer any questions. Here's example of a checkout abandonment popup that shows on one of our client sites when someone leaves checkout before finishing. (client specific info has been removed)
3) You can custom integrate HikaShop with
remarketing tools like Facebook. Facebook has an event for "Begin Checkout" that can be triggered and then it is cleared by the "Purchase" event. If the person doesn't finish checkout, you can target them with ads in Facebook along the lines of "Did you forgot something, or have trouble?", and can even show an image of the product(s) they left in the checkout if you have also integrated your product catalog with Facebook.
4) You can do something similar to (3) above with other
automated marketing tools like Drip, Intercom, etc., once you have them integrated with HikaShop and Joomla.
Hope this helps!