Comment by kelnos

That doesn't always work. A lot of phone numbers out there are "dirty": they are on various marketing lists and will get spam calls and texts.

Some carriers do try to keep excessively dirty numbers inactive for a while after a customer cancels a plan and returns the number, in the hopes that the spam will fall off after to many "this number is disconnected" responses.

But sometimes they don't bother, and sometimes it just doesn't help all that much, because spammers are just running through the phone number space.

This is a long way of saying that even getting a new number doesn't always work. The number you end up with might already be inundated with spam.