Try this
https://www.bitrefill.com/ they accept bitcoin deposits and you can top up any mobile around the world.
There rate is also quite cheap compared to what others have.
do you gurantee of its legacy? and also have you tried it before? also how much time it takes to complete the process?
bitrefill is the most known site for such service , so you should be good with it
sadly I'm not able to use it , when I first discovered the site it was shown that it supports one of the mobile providers in my country but when I tried to refill my mob I was getting error messages
one week late they removed my country from supported countries
but you should be fine with that service , if you don't want risk a lot try it first with the minimum