Flight SGJYKM paid twice

Good day I made this booking on my mango app on the 29th and immediate clearance eft as per proof of payment attached forwarded to ********** and ********** on the 29th May 2019. I called the mango call centre yesterday and spoke to Mihlali and she said that my flight status wasn't fixed on the system and that i must go to the mango reservations office at Cape Town International Airport and make the same payment again of R850. 92 which was completed. I was advised that I can request a refund today the 3 June 2019. Petronella just sent me an email to say that only one payment can be found and that no refund will be processed. Payment was made on the 29th May 2019 and as requested by Mihlali from the Mango Call Centre that i had to do another payment at the Mango reservations kiosk at Cape Town International Airport on Sunday which was done.