Call Centre useless for telling which store can SELL me gas

I called the National Call Centre to check is a specific store had gas for refilling. I was told by the agent, that they did have gas in stock, and the price per kg. When I got to the specific store, the security lady at the door of the store told me that the machine to fill gas canisters was BROKEN! So yes, they did have stock of gas. But NO, they could not actually sell me any!!!! What is the use of that? I specifically called the Call Centre so that I didn't WASTE time and petrol! What a useless Call Centre if they can't tell me that it is NOT worth going there, as they are not actually ABLE to sell me the gas!!!! COMPLETELY USELESS!