It's the one I've had for years and it's registered in my name as well, I forgot before to verify my e-mail adress so I thought it might be that but after I verified it, it still tells me it's invalid or in use.
It appear system unable to recognize the number as valid mobile number. Kindly add 1 after the country code. Example +52
1552217XXXX. Once you have update your number, please try to verify your number again.
It still doesn't accept it, it tells me the same thing about not valid or in use.