Cannot Activate Showtime Anytime App

A month ago I added Showtime to my DirecTV Choice Satellite package with the intention to stream some series. When I try to activate the Showtime Anytime app, I get an error message saying I don't currently subscribe to Showtime and to contact DirecTV if I've received this message in error. (I have no issues with the HBO Max app, which I get from having HBO through DirecTV.) I have repeatedly called DirecTV tech support as well as emailed support at Showtime Anytime (who said they are working with DirecTV to resolve the issue.) After almost 3 weeks, the issue is not resolved. Supposedly my issue was "escalated" to Tier 3 and "the back office" at DirecTV who was to call or email when resolved, but I have heard nothing. Feeling frustrated and would appreciate any assistance.