MMI codes on Galaxy A15

[Members_MwAamW0]

I'm rather regretting buying an A15 - there are so many things that are supposed to be available on all Android that aren't on the A15. The latest is that the MMI code to change the ring time before going to voicemail doesnt work. In fact all MMI codes don't work - it says they are invalid.

[-Robot-]

You should contact you network provider and they can do that for you