Reavelation of pricing when communicating with a c

This morning 01/07/2015 I went to vodacom shop as instructed by the call centre to make a sim swipe,I was then instructed to get an affidavit.The sim swipe was then done,when the lady who was doing a sim swipe was done I was instructed to pay R63 that I was not informed about,I then refused to pay an amount that I was not informed about from the beggining.she then kept my sim card and I need to use it.