Poor Customer service

The poorest and rude agent, I had a loan with old mutual, I paid it up last month, received a paid up letter confirming that I have fully paid my loan, this morning to my suprise I woke up with my account debited by old mutual, when I called them I spoke to Sindiswa, who said I am complaining to the wrong person it is not her fault that my money got debited when it was not supposed to, she is not the person that assisted me therefore I should not complain to her, when I asked her to put me through to a person who can assist she hung up the phone! that is rude and annoying!