First things first: I was doing Twitter a lot back in 2013-2015 but I then stopped and just recently started again. Back then the phone verification was done over a text, so you could pretty much use any text service or find apps on the phone that gave you access to numbers for texting. But now they seem to have changed this to a phone call instead (at least for me). So here is the thing, I'm doing kind of a gray hat thing where I need to be using the API (so phone verification is needed.) I also whish to keep the access to the number in case I need to re-activate the accounts. Another thing is that sim-cards are pretty expensive where I live. 10€ for a sim and then I need to refill it with 10€ to activate it. And then there also is a lot of fuss to keep it activated. So what is the best/cheapest way to gain access to phone numbers that I can keep (for at least a year before I have to pay again/renew in another way) and receive calls, and can be used to activate twitter accounts?