Frustrating incompetence of GPAA (non-payments and non-response to enquiries and complaints)

My wife's 2 siblings received their payments on my late father's death benefit claim (Pension no. ********** 9, Persal no. ********** 3), and her's was not paid because she needed to submit updated banking details. She submitted all the required updated documents on 12 April 2018 and she was assured that the payment would be made between 04 and 06 weeks. Today, 28 June 2018, is be exactly 11 weeks since her submission and she has neither received any payment nor feedback on the non-payment or progress of her claim.

She wrote to ********** and further called ***requesting a formal update or feedback on her claim, so as to know what she should do next regarding her claim. After holding 30 minutes without any assistance, I was referred to ********** but the e-mails are is bouncing back.

She is really frustrated and do not know what else to do.