No refunds even after given wrong pricing info

I phoned Transunion initially only to obtain my user account info. The lady told me since i already got my annual report this year, i can subscribe to a report plus alerts for R80.00. I thought this was't so bad so I said okay. When my invoice came afterwards, i saw they were going to debit R280.00. I phoned them to stop the order which they said they cant do, coz its MY job to confirm the price with them? She took my account details and never did she say: so to confirm, i'll be debiting your account with R280.00. I don't get paid to do their jobs? I am a customer, how would i know their pricing. They should inform customers correctly. coz there i just lost almost R300 over nothing...