How do I turn off voicemail on my iPhone?

Under normal circumstances, iPhone can turn off or cancel voice mail, as shown below:

(1) Write the short message "GHZ" and send it to the port 10658 1 12 to turn off call forwarding;

(2) In the iPhone, enter "Settings-Phone-Call Forwarding" and turn off call forwarding.

In addition, how to query the call forwarding settings of iPhone voicemail:

Go to Settings-Phone-Call Forwarding in iPhone to check the call forwarding settings. When the call forwarding setting is turned on and the call forwarding number is 12599, it is the normal setting. When it is found that the call forwarding function is not turned on or the call forwarding number is not 12599, the user needs to manually complete the setting. As shown in the figure