FNB not able to provide swift documentation for return of funds.

FNB are the intermediary bank for Bank Windhoek who via the swift system instructed them to return R74K to HSBC on 15.6.2023. One of their call centre people tried to help but the funds as of 3.8.2023 cannot be located by HSBC. Despite many requests for the funds to be traced FNB are unable to prove me with proper swift documentation so that HSBC can trace the funds and I am left in limbo.