Double payment for ONE sms bundle

On 30 Oct i requested a sms bundle to be activated on my line. The gentleman i spoke to misunderstood and activated an once-off bundle, although i wanted a monthly bundle. He immediately cancelled the once-off bundle and activated the monthly bundle. I was however billed for the once-off bundle and the monthly bundle, although i requested and received only one bundle. I spoke to a very rude lady with the name of Candice and requested the amount for the once off bundle to be removed. She logged a complaint and i received a sms stating a credit for the once off bundle has been requested (on 5/11). This morning when i received my account via mms, i saw the once off bundle is still on my account, as well as the monthly bundle. I am not paying for something i never received OR requested, so i would like this amount to be removed from my bill immediately, please.