That's not correct, maybe they have done it for you but it's not correct. Medicare nor any other carrier has authorization to "CHANGE" a date of service nor should they. The correct way is for another claim to be submitted. We don't ever want the carriers making correction to claims.. ever. If the claim was electronic yes you can re-submit it and call them to let them know the correct date of service was submitted and to back out or adjust the previous incorrect claim.
See, I didn't know that either! It's not my field, but GOOD to know, period.
The same rule applies in a medical office to patient charts... you can correct an error, but ONLY by lining through the entry once, annotating it as an error, dating, and initialing it, then writing the correct data. NEVER EVER is white-out used in a patient chart/medical record, or black markers, nor are pages removed, thrown away, and rewritten and then reinserted. That's a BIG no-no. Those are official records and legal documents.