Transfer Between My Accounts not Done After Two Days

I transferred money from my one Standard Bank account to a different Standard Bank account, also belonging to me on 16 May. The money has been debited to the first account but has not been credited to the second account. To make matters worse, the online statement for my first account says that the transfer took place today, 18 May, This is not true. Why is Standard Bank's system telling lies? This is not the first time there has been this date issue with Standard Bank's system. Also, how long does it take for me to transfer money from my one account to a different account I also hold with Standard Bank? This is ridiculous. I am losing interesting on the first account and being charged interest on the second. That is unjust.