Billing Matter!!

My mother has been with Vodacom for many years she is 80 years old, she had an extra contract which expired in December and was not aware about it, she went yesterday to Vodacom shop in Greenstone to find out when it expires she she can cancel it, when she got there the lady at the store checked for her and told her that it expired in December, so she asked her if she can cancel it and the lady said she can only cancel it in April, this is really not right to treat loyal customers in this way if it expired in December that should cancel it immediately or phone the customer to ask if she wants to renew or cancel. Very dissapointed as she is a pensioner and now has to pay extra money for 3 more months.