FNB lost our investment money!!

Money paid to investment and FNB cant find it and just say its gone!!! We paid money into and investment account. The account number and all were correct. The 1st payment went into the account. The 2nd payment of R40 000 did not went in. After we struggled and checked with investment party they checked on their side and even with our side show money is paid over it did not show at their side. When we asked FNB to check they made excuses and long story short our money is gone. R40 000 hard earn money gone. FNB must be liable for this as I want to know where that money is? Who stole my money. How can you pay it to an investment account,account number is correct and its gone? Who is *****ing our money! I will tell people not to use FNB if this is not resolved.