Day light ******* by Vodacom

I just tried to cancel my contract for data and I was given the highest cancelation amount ever. So Vodacom wants me to pay R7000 for a data contract that I paid 378 a month for. I only got a modem when I started the contract so I don't understand why I have to pay R7000 for R1000 modem. I tell you this is day light *******. Where will I get R7000 for a data contract cancelation.