Upgrade offer Not corresponding with A/C

My daughter was called on 21/10 with an upgrade offer by Nazreen. She was offered the special on the A3 Samsung @ R229pm all inclusive. As my husband CM De Villiers is the account holder he to spoke to Nazreen and she confirmed the new upgrade at R229..... but the last two statements received are for over R500.... how is this possible.? Please look into this urgently, rectify and pass the necessary credits and kindly ensure that the debit for this month is not R517 as per the new statement but the R229 as agreed with your consultant. A/C ***..... contact ***/***