someone reset my rank i think

i lost my rank it reset during a campain game and all credits and i cant play matchmaking or anyting that involves other people

You could have been credit banned/reset for cheating or unfair boosting of some sort. If you got reset randomly whilst playing and you haven’t done anything wrong, then reset your Xbox and router/modem and see if that resolves the issue. These things can happen every once in a while.

i tried it still dont work does anyone have 343 service number

That’s what this thread is for. It’s even stickied for your convenience. If you’re sure you got reset, post there and somebody should answer your questions.