You can attach same payment receipt with your new application. Get both your photos stamped and write name on both to avoid any issues from IRCC end.Just to update those who may have a similar issue:
I called IRCC and they told me that whether my unstamped photo will be accepted or not will be at the discretion of the agent processing it. That being said, they recommended to mail in another application (dated August as @rafzy suggested) with new photos and an LOE. So that will be what I'm going to do today.
Many thanks for your support!!