OP, just buy a real GB phone number from
https://smsprivacy.org/ for 0.0015
BTC per day. It's a hefty price tag but they give you real numbers, not VOIP numbers, that also work on big sites like Twitter and Facebook, and you can use it on as many sites as you like. The more sites you register the phone with in one day the more value you get out of this purchase. You can cancel the number when you're done with it.
(No, of course I'm not affiliated with that site.)