cheated off of my airtime

Hi .. on Sunday i loaded R80.00 worth of airtime, within an hour it was depleted. Called in i was told i had made a call to an 083 505 number for 0:28 sec the the rest was taken by internet R76.00 for logging in for 3min. May i please have a break down of this as i find it hard to believe. I will compare this with my internet history. really guys can we just get along until i cancel my contract.