Airtime not working after recharge

I can’t use my airtime after recharging, for me to make calls i have to call mtn first, the last time i called they said i must go to the mtn shop near me, today i took my time going to the mtn shop at quagga centre, the guy told me he doesn’t see a problem therefore can’t assist.. the issue is frustrating me because i can’t make calls. During an emergency there’s no way i can call mtn first, im frustrated and the guy at quagga is mean with too much attitude.