Removing a face PERMANENTLY from Faces

I am trying to tag myself in Faces, in the new Photos App. However, it keeps reverting it to an old Face file that was my name in capital letters (my current face file is my name in lower case). Everytime I try and tag myself it automatically adds the photo to the old Face file that I have deleted, even though I have selected the new one! I select the new one from the drop down menu and all seems great and then I press return to confirm and BOOM it brings it up in capital letters and has added it to the old deleted face folder.

Therefore, every time I try and tag myself, it automatically changes it to the old file

In iPhoto you could just merge the two files so if, for example, you had two "faces" one called John S and the other was tagged John Smith, you could just merge them into one (if they were the same person). You cant seem to do this in the Photos app.

The reason I wish for the one without the capital letters is so it syncs to my social media and automatically tags me when I upload. Never mind the fact that all my other pics are already in that folder anyway.

Its driving me nuts (like most of the other features in the new Photos app). Please help!