Someone answered this question in another post, by posting that it wasn't supposed to happen. It's a mistake so they should be fixing it soon.
probably a glitch or a bug ... i had two myself and also you kill streak continue to add up so if you manage to get 10 kill again youre gonna have another one for free... they will probalby fix that soon ahahah not on ps3 off course
i play on ps3 and its were im seeing it... me and some friends went into a private match and i found out for myself the deal with it... hope it gets fixed soon :/
yeah I'm sure they will lol I'm sure they have tons of tweets right now complaining about it.