Civil service pension scheme owes me £21,300, five months after retiring

Scheme has not replied to complaints and Pensions Ombudsman says it needs evidence of thatI retired from the civil service five months ago and Ive still not received my pension. Ive complained to the Civil Service Pension Scheme (MyCSP) repeatedly, but it doesnt reply.The Pensions Ombudsman says they need evidence that MyCSP has not responded to my complaint. How can I provide evidence of a failure to reply?