Delays in paying my refund

I have been waiting for my refund since December last year, but the process has been continuously delayed, with different people handling my query. On January 31st, I was assigned to Gugu, who assured me that the refund would be processed within 4 to 6 weeks and confirmed payment by March 7th. However, to date, I have not received my refund. Yesterday, I followed up with Gugu and copied Michelle, who was my initial contact regarding this matter. Michelle then informed me that Gugu is no longer with the organization. When I asked for a timeframe, she did not respond. I have provided all the required documents, yet my refund remains unpaid. I would appreciate a clear and immediate resolution to this matter, as I am extremely frustrated with the ongoing delays.