I have a new iPhone 5C. Recently I've had issues that my voicemail box has been full for a while. I have deleted all in the voicemail location under PHONE. I have also erased them permanently. I tried calling in to my voicemail to delete but it just asked me to delete them soon and offered me set up options (no deleting options). I tried pressing 7 anyway, no luck. Also, if you go to voicemail now, its completely blank and empty besides editing my greeting. There is no way to even access old VMs. I looked in General Settings and Back up for voicemails, nada. Any suggestions?
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Everytime my phone goes to VM it says the VM is full and can't take any messages. There are no VM messages. The've all been deleted and the deletes cleared. So I reset the network settings like suggested. What would that have to do with the voicemail? Anyway, it didn't solve the VM full problem (of course).