Five shillings left in the Municipal Bank

I remember the Municipal Bank on Kingstanding Rd. In 1945 to 1948 I was in the RAF. I used to have part of my pay sent home to my mother who would deposit it in the Municipal Bank. When I was discharged from the RAF I went to the bank to draw out the money. The lady Teller persuaded me to leave Five Shillings in the account to keep it open, ” incase I wanted to use it sometime in the future”?? so I did. I never did use it again and I wonder if I ever received any interest on that Five Shillings. I’m now in my 80s maybe I’m a rich man and don’t know it.