I don't think there is much you can do about it, and figure that 90%+ of the time, you'll probably get what you ordered. There are so many things that can "go wrong" in the distribution of that coffee - from the employee loading up the wrong grounds into the wrong canister, to the employee taking coffee from the wrong canister without noticing, or the employee putting the decaf pot in the coffeemaker under regular grounds, to the employee just putting regular coffee in your cup without paying attention.

If one has a health situation (other than sleeplessness from caffeine), then it would be wise never to order coffee in a restaurant, unless it was Sanka, in a packet. (Oh, memories of old relatives in coffee shops 40 years ago!)