fales billing and false contract

2013 December I took out a 3g contract with fnb for R200 per month <br> in January 2014 cell bills R1,322.46 I took the matter up with fnb and stopped the debt order, then in February 2014 cellc bills R2,720.82 I contacted fnb again and no one at fnb could tell me what's going on. Then a wendel from fnb cellular contacts me to sort the problem . we managed to have it closed and terminated.<br> now cellc gets daly to contact me to demand R302.10 for a account that was closed and terminated by fnb