I would call your vet and ask him to call you back when he has a minute (rather than discussing the matter with the vet tech that answers the phone) shouldn’t be a charge.
It depends on what type of bladder stones your dog has as to what you can add to the diet.
Ask the vet what you can use for a topper to mix with the prescription food. For example, dogs love a spoonful of chopped up broiled chicken liver added to the meal.
And, add water to the meals, frequent bathroom breaks to keep the bladder flushed. I find that 4 small meals per day instead of 2 regular seems to help too.
