How to reactivate my account

I have a backup phone number. It hasn't been used for half a year. I mean, I haven't pay for it for half a year. Today, when I wanted to use it, I found that my backup phone said "sim card not provisioned". 

I've tried to login into my account. However, I forgot my password, and I cannot reset it since I cannot receive text message.

So I really wonder how to reactivate it. Thanks!