Got lost driving to the bank today.

I'd only been to the bank just the once, two years ago when I opened the account. Never had a need to go again until yesterday.
We received a refund check for our tax disc because we sold one of our cars. Is it a pain to pack the baby and his pushchair into the car just for a mere 5 minutes spent in the bank making a deposit? Sure, but hey, that's life. So there I am, driving around all these one way streets, with a general idea of where I know the bank must be, but I just couldn't find it for the life of me.
Why can't I make a deposit at a nearby HSBC cash machine?? Why? WHY???