To enable push notifications on your iOS device please follow the steps below:
Step1: Navigate to Settings -> Notification Center -> Voxofon app
Step2: Enable all options there
Step3: Log in to Voxofon account
Step4: Navigate to Account tab
Step5: Navigate to Contacts and set Check contacts on (If it is already checked, try to uncheck and check it again)
Please let us know how it goes.