Please remember as a Local Guide to always respect the Business and its customers:
If you don’t know an answer - skip it. Don’t suggest “call the store” or answer “I don’t know”
Don’t recommend or suggest business competitors (ie Sam’s club doesn’t have a product or service but suggest the customer solve their issue by going to Costco instead).
Indeed those “call the store” answers are no doubt in a lot of cases an easy way to score another 3 points. A more elaborate version of that, however, can be an added value - and is in fact one I am using regulary: in case the business is not claimed, and especially if previous questions have been left unanswered, I do point out that the business owner is most likely not aware of the fact that there are questions on Maps, and then include their telephone number suggesting that as a more efficient way to get in touch.