Gamertag for Xboxlive sudden change

Hi,

I was setting up an Xbox live so I could play Minecraft with my friends but once I created my gamertag and exited for a moment, it changed to my recommended name HumDrumCow39612 which I don't want as the gamertag, what I chose was vexrve since verve was
taken and I added an X to it so it could be available, can this be fixed without me having to pay and get it back?

:)