Your system is returning SVC0900 - User status error. so you need to check the user account on your side. It appears the last successful purchase was on 2015.04.30 and you started sending the SVC0900 error on all purchases starting on 2015.05.12.
Also, we noted this user/MSISDN attempted a purchase today (2015.09.14) but it failed due to an Invalid PIN.