customers don't think, or realise implications their actions have on your business. and more often than not don't care.
but remember if you knock that dish off signal they won't b happy at sky's call out charge, and guess where they will come knocking then?!
I'd explain its awkward and the risk of knocking it. if they are happy still, next price increase I'd add a slight amount on price extra.
our prices are reviewed every Jan. customers always seemed to expect prices to go up then anyway.