... the phone for a long time.

🔹 First of All I would like to thank @AllisonR3333 for keeping my book going! 😊 - cause she's most probably the user whose questions I answered the most often here

Now I must say that I understand you - & such a thing happened to me - not with phone, but with twitter: My twitter friend I had no other contact with once suddenly 'disappeared' ( that is: stopped tweeting for an unknown reason - then started a new account a Month later & messaged me from that new one cause she just stopped using her previous account ). 

So as we both know, such thing happen in life: People may stop contacting you for various reasons - or ( as it was in my case ) For No Reason at All ! 😐 - that's also possible.

I had no other contact with that friend - so I could only wait till she comes back online - & she did, after a Whole Month! - but she finally Did! 

And if you have any other contact with the friend you have in mind - for example if he uses social media: try to check if he was active recenly & contact him there. 

- If he wasn't active: You can only wait till he answers the phone - or maybe He calls you Himself

*( I hope you won't have to wait as long as I Waited for My Friend to come back )