Maybe it was the sudden release from stress but the wording really tickled me. Not "a refusal often offends," but "we do not wish to offend."
Customer: "Um, can I pay for this later?"
Shop owner: "Oh man! Now I have to do ths: You rotten stinking mongrel sonofabitch cheapskate bastard! Piss off and never come back! Sorry about that but... You know?"
A sign I would like to see is "Please ask for credit so we can offend you." The shop would fill with middle-aged besuited business men who missed this week's appointment with Mistress. "Excuse me miss? Can I pay for this later?"
I see a chain of BSDM fetish clubs disgused as corner stores staffed by strong ladies in shiney black clothes. "Just going out for some milk, dear!"