When I order a drink here (or anywhere), I almost always say 'Coke or Pepsi, please' since I don't know which they offer and I don't care which I get.
A couple evenings ago I was wandering in the Colon district and stopped at a bar/resto ('resto' is the local term); they have a few chairs on the sidewalk and I could sit there and watch the passers-by. Since many of the passers-by are female and attractive, this can be an enjoyable way to pass the time.
The following conversation ensued:
Me: Coke or Pepsi, please.
Me: Yes, Pepsi, thanks.
Waitress: We don't have Pepsi, Coke only.
Me: Okay, Coke.
She brought me a Pepsi.