the simple answer is that your windows will be clean despite the ice. when the ice melts if they are not up to the expected standard please call me and we'll come back.
Yes, spot on, but write it, don't text it, then wrap the note around half-a-brick and...
No, don't, I'm only joking.
And neither should you strew a handful of carpet tacks over their drive; defo not.
Personally, I'd consider all these 'nasty options', then I'd let it go, I wouldn't reply to them, I just wouldn't go back either.
Flip 'em!