Your doctor would need to call the pharmacy to let them know that you are to continue your current dose until it runs out, and then switch to the new dosing. Otherwise the pharmacist has to assume your doctor intends for the change to occur now.
I recently had a prescrip changed for a pain med I get monthly. The dose chg was minor, but the pharma upon getting the new script computed my refill now based on the NEW instructions, not waiting till the current dose was done.
What action do I have this is not what the Doctor intended ?
The depends on where you are, as laws vary. I would suggest you contact the pharmacy that flagged you to determine if any action is being taken.