Sunday surcharge at the barber?

First time having to pay a Sunday surcharge at the barbers.

I work 6 days a week and only have Sundays off. Went to the shops for some groceries and decided to have a haircut. I usually go to my local barber but since I was there, so just went in.

When paying the barber asked cash or card, I said card to which he informed me that there will be a surcharge. I thought it would be the "usual card surcharge".

But no. Apparently the surcharge was a 20% Sunday surcharge.

Is this new? or have I been scammed?