Cash Deposit Not Reflected in 4 Days

Hi, Last week on Thursday the 12th, I made a Cash Deposit via ATM to an FNB account, recipient staying in UK. I’m from South Africa. But it still hasn’t reflected until today, it’s been 4 days. How is this possible? The last 4 digits of the account number is ***7484 and the reference is BX31JFMT9