Hextech crafting system double crossed me!

I was curious on buying the 10 hex tech chest and keys bundle, so i bought the bundle and when i started opening them i realized that it gave me 20 instead of 10, and it charged me normally but then when i restarted client because i couldn't claim my champion or skin. So once i restarted and logged in and i saw i was -1059 RP. I dont understand why it charged me double when i just wanted one 10 chest and key bundle... Please help i do not want to get banned for this...