Disgusting Service!!!

My parents have been trying for 2 days to cancel 2 contracts with Vodacom to no avail. They have both been in a branch and called. They keep on getting excuses and upgrade offers that they do not want. These contracts are running on a month to month basis, so it's not like they are trying to cancel a contract early. Also, they have been paying for an upgrade they never signed or received!!! and is trying to get answers on this as well. but the people in the branch tells them to call in and the contact centre is telling them to go to a branch. Now what are they suppose to do? My parents are retired and cannot afford these contracts anymore.