I have a similar problem. I cannot get my iPhone to stop forwarding to one number. Even if I change the call forwarding number and turn forwarding off, it still forwards to the old number. Apple Geniui could not solve the problem at the Apple Store in Manhattan.
I have the same issue. I receive calls when the iPhone is on. When it is off or have no service, the number gets forwarded. I have call forwarding off but get the error saying it could not save settings. Apple support could not help.
I called At&t. They said my phone was forwarded to my voicemail. They reset this for me and now when my phone is off, it goes to my voicemail again. I still receive the error is settings though.
I had the exact same problem, after deactivating call forwarding the phone was still forwarding all of my calls to the house after so many rings. At which point, the house phone would record my messages, which I never check! I called AT&T and they deactivated my call forwarding feature and now it's back to normal. Until apple fixes this, anyone using the iPhone should not activate call forwarding as it will annoy you greatly.
I had the same problem. Even after resetting (as previously suggested), then restored (by Apple people), the guys at AT&T reset the call forwarding and all works fine now.
Just make sure those AT&T guys don't send you to Iphone support. It will save you a total two hours of listening to crappy hold music.
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Call Forwarding
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