Avatar problem

I have it so that you can buy and change other peoples avatar, and I see a Item that one can buy to remove a avatar given by another,

But doing some testing, I notice that instead of people buying to remove avatars given by other people, they can just go to there User Cp and click "Do not use an avatar", I have have all customer avatars disabled. when a register user goes in his User Cp all they see is a picture of the avartar and a radio button that says "Do not use an avatar", if they click that and save it, it removes the avatar.

Now that being said why have a option for people to buy to remove the avatar when they can just go into UserCp and remove it themself??
default for changing there avatar is 15,000 points and default for a person to remove a avatar given by others is 10,000 points. thats alot of points for something that can be deleted from usercp

Is there a setting i need to turn on or off, so that they cant click on "Do not use an avatar" i searched for like 2hours looking around tryin to fix that but no luck so far, can someone please help me??

Thanks