I have never billed anyone in Canada and therefore never collected GST, but get the GST i pay refunded every quarter.
The first time we submitted the claim, for hundreds of dollars, i received a phone call from the GST lady asking how this could be. What followed was a 20 minute conversation about what our business did – advertising of course. She then sat down with her IT rep and went thru my sites trying to “understand”. After a 2nd 90 minute Q&A about my business, the check was sent and no issues since.