How can I record and SAVE a CUSTOM GREETING on my iPhone?

I have tried several recommendations, but I STILL CAN'T RECORD A CUSTOM GREETING FOR MY iPHONE!!!

I really need a customized greeting and every time I record, I hear the playback and it sounds great, but when I enter save it gives me this error message:

Com.apple.mobile phone error 1035

Anyone out there who has more advice? I disconnected from wi-fi and used only cellular

I went to the keypad and held down 1, but nothing happened except hearing a long, long list of incoming voicemail messages...too many to try to listen to them all. And they can't be deleted due to information that they contain.

I'd really appreciate any help you have for me.