Wasting tons of money to pay for your calls and mobile internet definitely isn't a thing people want and I am glad that some people manage to find good options. By the way, I myself started to spend much less after I changed the job. Now I don't call that much so my mobile balance is huge. Maybe I'll just convert the money from there, just need to find a convenient way to do that. Yet only found this
link, maybe you can suggest some other options?