Unfortunately, if, when you created the account, you have not registered a secret question which you remember, or an alternate recovery email address or phone number to which you have access to receive a reset code, you cannot prove that you are the account's legitimate owner. Hence account recovery is absolutely impossible and there is no way around it.
There is nothing you can do if you created the account on the mobile device or number you no longer have access to.
Always create accounts on a PC or Laptop (landline IP), and then attach a mobile number to it. That way, you can have multiple ways to recover the account!