NON REFUND OF MY AIRTIME

I HAVE MADE A UPGRADE ON CELLPHONE CONTRACT IN SEPTEMBER 2015 WHERE IN PREVIOUSLY I HAD<br> 200MB, 19 SMS'S AND R119,00 . I TOLD THE SALES LADY THAT I WAS HAVING BALANCE FROM MY PHONE IF YOU UPGRADE WILL IT NOT AFFECT MY AIRTIME AND THE LIKE , MERLIN.<br> SAID NO. WE CONTINUED WITH THE UPGRADING, THERE AFTER MY BALANCE WAS ZERO . I TOLD HER SHE SAID SHE WILL LOG A CALL TO MTN. I AM NOT HAPPY BECAUSE FROM LAST YEAR I HAVE BEING GOING UP AND ABOUT BUT WITH NO ASSISTANCE WHAT SO EVER.<br> I WAS GIVEN THIS REF NO TO CALL THEM REF ***, REF ***7, REF ***, REF*** PLEASE HELP MY CELL NO ***