Espresso on ice? No. But a VERY short iced Americano, using a little water to ease the temperature before adding ice is ok. And you shouldn't have your cream out and/or accessible to customers. You should add the appropriate amount. This is better service to the customer, and it completely eliminates the type of problem you are talking about.
As an owner (says your profile), you are the one who needs to decide and enforce your standards, they are not for the customer to decide. As I mentioned, remove the cream from the counter to eliminate access to the problem and guide them to a latte as you are rightly doing. And a 16 oz cup is a 16 oz. drink.
These people who try to cause problems or find a work-around to paying for what they are ordering are not your customers. They do not support you or respect what you do. Wasting your time and energy on bad people is not productive. Focus your energy on providing excellent drinks and service to all your great customers who actually do support you, when you do that you will get more long-term customers, and these types of issues will virtually cease to exist.
What John wrote.
I'll also add: if you don't have the cups then you can't make it anyway. When the very rare person has come into our shop and asked for espresso on ice, we serve it to with in a 4z cup with ice.
And we don't have a condiment bar.
These things discourage that kind of behavior in our shop.
I completely agree with the previous 2 posts.
We had a policy of charging for the cup size, not the cup contents, for exactly this reason. You have to price your drinks based on everything that the customer is going to get - many don't understand that the cost of a little cream is built into the drinks that might use it. If you have a super small cup that will take care of much of the issue.
It's unfortunate that so many people think this is acceptable. Your position is completely reasonable. Good luck.
Ask 'em if they want cream in it. If so charge 'em for a 16 oz latte. If not they get the smallest cup you have. John is right. These people do not wish to support you. They wish to take advantage of you. If you end up making them mad and never seeing them again you'll end up saving your business money on the spot and in the long run. Plus you'll keep your standards up. Creeps.
Say yes and thank them for their business. Provide them good customer service and earn their trust, then you can start suggesting to them how they should drink your coffee. It's not worth a negative yelp or Goggle review because your COG's went from 15% to 50% of one $3 transaction.
A customer is not someone who comes in and simply pays you for a drink, a customer is someone who supports what you do. The mindset you are advocating is the same as the parent who gives the child candy because they cry when told no. And it's equally obvious that these people were once those same whining children.
You may get a negative review, but intelligent people see through those, or see them as they often are, a positive. The, "I ordered an espresso over ice and they wouldn't give it to me." review would be seen by actual customers and future customers as a GOOD review.
A Brazilian customer of ours said it best, "In Brazil, I can make steak at home any time, but when I go out, I go to taste their steak. If I wanted my steak I would stay home. So I come here because I want to taste your coffee." It's sad that the only problems most shops here have are with Americans. Foreign people tend to have a greater respect for food and the craft it takes to prepare something excellent. Big thumbs down on the entitlement mindset.
We price our iced double espresso same as an iced latte. I never get slack either way about price. We focus on serving great espresso and they keep coming back. I think once you start worrying about what they are going to add to their drink, thus driving up your cost you lose that customer service edge and its starts getting uncomfortable. But if you price your items to already account for those scenarios you eliminate that bad feeling that could arise.
Thats just my opinion.