70% Discount

So on 14/09/2017 I received an sms from Creditworx stating that I qualify for a discount of 70%. Called the number provided, the consultant advises me that the amount outstanding is R7212.97(nevermind the amount they gave me 2-3 days prior stating I owe R6639) and with discount I will have to pay R2600 (odd rands)....... I asked her how she got to the amount, she says the system generated that amount!!!!!!!!!!! According to my calculations: R7212.97 x 70% = - R5049.08 R7212.97 - R 5049.08 = R2163.89 that I must settle in full, the offer is valid until 31/10/2017. I told her I can settle the amount (R1067) but not according to their calculations as that amount of R2600 is NOT a 70% discount.