Old Mutual not paying as per contract

My annuity should have been paid on the 1st of July. Tried to phone and email them numerous times even visited one of their branches but to no avail. Only message from them is be patient because high call volumes... In the meantime there is no means to communicate with the. The worst service I have ever experienced. They are quick to take your money but if it comes to pay out then you will have a really tough time.