Vodacom - No compassion!

My mother passed away recently and we would like to cancel her contract. The contract is in my sister's name and has been for many years.

We have received very little assistance from Vodacom regarding this or have been told to pay 90% of the contract which amounts to R20, 000.00. Surely if someone passes away, there should be an exception? This is ridiculous and unfair, and if not sorted out, we will all be canceling our contracts with you.