Late Payment in my credit report over R50

On the 29/01/2015 I asked the cashier to pay my full account and the food at the till cash. She only payed the account and charged the food to my account. Thinking my account was payed off, i did not expect to pay woolworths anything. March I see an over due payment. Now My credit report reflects a late payment. Please notify transunion that this was not a late payment. Why must this show on my credit report for 2 years for your fault? It is only now that I picked this up as I was reviewing my accounts and credit report. You can see on my February statement what happened.