Mtn ****med my airtime and gave me data

This morning I was surprised that I ran out of airtime and tried to call customer care of which I was refered to mtn store. They told me that their system is down but with my phone they checked all the subscription of which the is none. They said due to the system I must come back after 30 min. Using mtn app I have been checking my balances was not reflecting. I calculated my calls from the time I bought airtime to now which is 16 min all in all. So now I'm checking again on the app it shows that I have bought 1gb data for a today. I don't know how because my 1st time using my phone today was when I tried to make a phone call and realized I ran out of airtime from there I have been trying to figure out how. How is it possible if it's not ****?