Warren Fenty lost his cool after cross words with the other customer, who was later sectioned under the Mental Health Act, at lunchtime.
As the 19-year-old's mum was ushering him out of the Trowbridge HSBC he slipped past her and ran at the other man. During the shocking scuffle, caught on the branch's CCTV, he picked up an elderly man's walking stick and wielded it at the other man.
After leaving the Fore Street bank he was arrested coming back while armed with a lock knife, assaulting a policeman in the struggle.What a lovely example of modern youth...
Cathy Thornton, defending, said he had gone to the bank with his mum to get a new debit card when an issue developed between him and the other man.
She said he was annoyed at the way the other man had spoken to his mum and wanted to let him know.
He got the knife and returned as he wanted to ensure his mum was safe, she said, and never got it out.Hey, we've all been there, right?
Passing sentence Recorder Malcolm Gibney said: "Miss Thornton urges upon me that you are polite, respectful and remorseful.
"You were everything but on March 29 this year when in the Trowbridge branch of HSBC attacking another man: a man who it turns out has mental health problems, in circumstances where you may have been verbally provoked.
"It is clear from the CCTV footage you were the aggressor. Despite the best efforts of your mother to leave the bank you forced your way past her, went back, and challenged the other gentleman."18 months! He won't serve it all, of course...
H/T: @MavisStott via Twitter