In UK I just called a special number to disable voicemail. There's also a code you can "call" to set the time between "no-answer" and "divert to this other numb

In UK I just called a special number to disable voicemail. There's also a code you can "call" to set the time between "no-answer" and "divert to this other number that's your voicemail" I almost never call/sms anyone from my phone, so it costs almost $0/year to run