Wrong, not only it stays the same bank as before in Slovenia, but there is not such a thing as Unicredit UK. They only switched the company to a UK one.

https://www.bitstamp.net/article/new-banking-details/

Dear Bitstamp clients,

We would like to inform you that Bitstamp now has new bank details.

We ask that you send all further deposits to following bank account:

Account owner:   
Bitstamp LIMITED
Address:   5 Jupiter House, Calleva Park, Aldermaston
City:   Reading, Berkshire RG7 8NN
Country:   United Kingdom

Bank name:   
Unicredit banka Slovenija d.d.
Address:   Smartinska 140
City:   1000 Ljubljana
Country:   Slovenia
IBAN:   SI56290000170073837
BIC (SWIFT):   BACXSI22