I've tried the #67# code and my phone comes up with an error message saying that "Call forwarding service has been disabled".
I have a Motorola Moto G 2nd gen.
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I'm really sorry you're unable to delay the voicemail time. So we can get this sorted for you, give us a call on 789 or 0345 6000 789. The team on the phone will be able to get this fixed in no time.
Let me know if you need anything at all.
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