20gb + 20gb Black Friday special for R199 irregularly billed

In November we signed up for the telkom movile data deal special and according to our understanding the bill was set to R199 monthly and if the data depleted we had to wait till the 1st of next month to access contracts data during the month of Jan as per norm with telkom the debit order went of for R489 and we thought it was for sim connection and subscription fees, Today we received a bill for R1300 and odd rands when we queried the bill we were told that over and above the R199 theres R500 allocated for usage and that has not been app**** for by anyone to access the additional allocated amount and if we wanted more data and a higher bill we would have taken a higher data allocation contract , we are not willing to pay over and above the subscription amount as there was no agreement enterned into by us and telkom with regards to accessing the additional amount allocated on the contract