Bad Customer Service

My Dad in his late 70's has now been trying for months to cancel his Connecta 50GB package. Every time he phones, he gets put through to the cancellation department and then the voice recording says: "They are experiencing problems and they are not available now" Really!!! How can it be that that department ALWAYS has problems?????? This is unacceptable. If you go to a Cell C Store, they say they cannot assist. You have to phone. So, what do we need to do to cancel this contract????????????? Is there someone in the cancellation dept that can assist????????