Sam Stothers Repairs in Belfast

I messaged Sam to see if he could look at our broken dishwasher. At no point did he state he charged a callout fee via message or when he arrived at the house. He was on site for 8 minutes, said it would be better to replace the dishwasher and asked my partner for £45. While my partner thought this seemed unreasonable, he assumed it had been agreed in advance and so paid. When I messaged Sam he said he doesn't tell people there is a callout charge unless they ask. I haven't personally encountered this from a tradesperson before, so just want to make others aware that this is the case.