I am available on Viber but my phone number is busy, how do I stop this?

[AC Question]

available on viber but phone number busy

Hey,

I could not find where to post a general question. I have a contact which is available for chat on viber. we can text each other but i cant call her ordinary mobile phone number. line is busy all the time. is it possible she has blocked incoming call but is only available in viber?