If you removed that app before then end of a billing cycle you should not be charged by shopify for that app.
If for some reason it's still billed you'll need to contact shopify support
Extended info on app billing cycle and process
Hey Meagen! Harel from Staffy here.
Staffy was always online but unlisted temporarily due to the development of the new version from scratch (of course, while supporting the previous clients along). We're back with our brand new version since August - and now we're supporting both Online and POS stores together.
As mentioned above - once you uninstall the app, it automatically cancels your subscription, so no worries here.
With that being said - we would be more than happy to welcome you back!
Wish you the best,