I worked in pharmacy for years, filling prescriptions and interpreting those doctor’s orders into a label. This is, frankly, negligence on the part of the pharmacy. If we made mistakes like this, or even subtle mistakes, they were sent back to be fixed. Your meds are probably being filled by an overworked pharmacist, working without staff, and cutting corners. That or your doctor is actually sending the scripts to the pharmacy with entirely incorrect instructions, which actually did happen quite often, as well as doctors prescribing strengths that didn’t exist.