Thank you for that additional information, that will be helpfull in allowing me to advise you today.
If the transfer of money to this other account was made by a bank error, ie they transferred the money to the wrong account, then the bank are at fault and must refund you your money.
However, if the transfer was made by the bank but using information supplied by yourself, then the bank are not legally responsible to refund your money. When I say information support;ied by yourself, I mean if you had supplied or entered and account number incorrectly, even bt mistake. If the fault was not made by the bank then they are not liable and would have only been following through with information entered by you.
However, the bank should try and assist you recover the money. They can contact the account holder who received the money if it is one of their customers, and if not they could contact the bank who's client it is to seek assistance.
However, if all that fails, then you can actually report the matter to the police. Because even though the money may have been transferred to another persons account in error, that person has no legal right to keep the money If they fail to report it to their bank and keep the money, it can be treated as theft. Very much like finding a wallet in the street and keeping it rather than handing it in to the police.