Disable Voice Mail iPhone button

[MatteoV]

Hi all, with iPhone 5s and iOS 10.3.3

• the problem: sometimes I touch, without notice it, the Voice Mail button at the right of the keypad key, in Phone environment, and I pay money because the phone automatically connects to the service (I've disabled my Voice Mail service with my sim company).
• the question: since my sim company said me that they can't do anything to disable the connection to own Voice Mail service, , when I touch the voice mail button, can I set my iPhone to delete the phone number of the Voice Mail service so that I don't risk anymore to pay with the button, as I don't want to use the service?

Thanks for any reply
Regards
Matteo

 

[MatteoV]

Hi, I'd like to ask you if with iPhone I can disable voice mail service, that user launchs the corresponding key. And how can I enable numbers in the virtual keyboard so that they are always visible?
Thanks