POOR SERVICE

I have renewed my mobile data contract yet to my surpise today i received a statement indicating that i am owing the amount i was paying on the previous contract. I called your contact centre on 081 180 and 10210 and was on hold for 1 hour, finally one consultant responded asked me a whole lot of security questions. After that she told me she can't assist as her system is down. Please assist me. Mobile number ***.