Sorry to hear that you need a refinement, but this is pretty common with clear aligners. Since you're not sure whether your dentist told you that refinements would be free or not, you would have to go with what you remember and believe that he/she is being truthful with you now. Generally speaking, it depends on your specific case. If you were in an express or limited case, then you will likely have to pay for refinements. If you are in a complete case, then a certain number of refinements would be of no charge. If your doctor is charging you for refinements, it is likely you had a discounted treatment plan to begin with and these are additional charges incurred. Good luck and I hope this helps. Follow me if you have more questions.
Sarah Thompson, DMD