mr A S,
I'm with you on the personal thing, some customers will be open and friendly and it's nice, even professional to be friendly back, however not ALL are like that unfortunately. (I spose we don't know what the customer may be having to deal with in their personal life or if they've had a really bad experience with a previous window cleaner/tradesman, although it's not a reason to take it out on someone else, it does affect people's judgement..)
I'm like you, I go the extra mile to keep them happy, (a walkover my missus says) but I believe it's good business practice, it's nice to be nice, specially in the times we're living in. I'm definitely not cutthroat enough, and I'll never be rich, but that's not my goal so I'll carry on as I do. Your text replies to the guy are worded almost exactly as I probably would've typed, so I can see where you're coming from, unfortunately, although you've done NOTHING wrong, there are always going to be unreasonable control freak customers out there. NOTHING you can do about it matey, you've been nothing if not accommodating, no charges of obnoxiousness could be levelled at you, just forget it and move on.