Another incorrect contract

My 100G data contract ended in March. And vodacom automatically put me back to an old data plan which was 30G for R200 3 years ago without my consent. Now that 30G that put me back to is R600. I've calling them asking to cancel it and put me to a better plan but nothing. They even promised to pay back all that money they deducted. They never did nor stop deducting money from me.

WHO WANTS TO PAY R600 FOR 30G?? Please help.