Suspended line

My sister was called Vodacom offered a Phone (Tablet) the phone arrived and she was told if she was not happy she can return it in 7days. She didn't even wait for 7days and returned the phone. They debited R350 without her knowledge which she immediately reversed from her bank. Now her current line is suspended Vodacom says they owe R754.28. She is more than annoyed and wants nothing to do with Vodacom. She can't make and receive calls. Please sort this out immediately. Call on ********** 958 or ********** 399