Annoyed and dissatisfied

I resigned from my previous job and I've called the Old mutual call center a few times and I must say its the most annoying call center I've ever come across, my provident fund is with Super fund and every time I call their call center I literally hold on for more than 30 minutes I do understand that there are call volumes but I have a feeling they doing this on purpose knowing very well that people who call their call center have either lost their jobs or retrenched so I don't know where they think people get the money to hold on to the phone for more than 30 minutes. I'm so frustrated by having to call them really.