Don't worry, if you've entered all the right details and information, and the funds just did not reflect in your recipient account, this kind of error can be reversed and you will surely get your funds back (though may take some time for investigation, etc. by the bank).
All credits and debits have to be transparently logged and audited, so if money goes out from somewhere, it has to end up somewhere; i.e. it cannot just disappear.
HOWEVER, if you made a typo mistake, etc. and entered the wrong recipient account number, then the money might have been credited into a wrong account. In that case, it might be more tedious to get your money back, since the error was not from the bank.
Make sure all your evidence are available and documented, to ease the bank's investigations.
Good luck.