Cell C
Duplicate Charges not corrected first time

I complained about a month ago about the duplicate sim connection charges on my contract. I was contacted by Nelly and she promised me a credit of the amount on my next statement. I did not recieve a statement nor did a recieve the credit of the Sim Connection fee. My debit order for the contract went out as usual one for the amount of the contract and a second amount i have no clue what it is for??? What happen to the credit i was promised