I tried it so many times some refuse to accept bitcoin and some accepted my payments, first time i tried it is when i bought a shoes from a surplus store and the cashier denied my payment because they are syaing that they dont know how to use that currency that was my first time, then i tried it again after several weeks and bought a gadget and i offer to pay in bitcoin and this cashier accepted my offer because they are using a bitcoin wallet. so the catch here is the technology it self some are knowledgeable and others are not.
Did they allow you to pay to them directly or did they use a payment gateway to handle the conversion? Maybe it's better to present them the available options to professionally accept Bitcoin, which could work out in their benefit in various ways. Accepting Bitcoin directly is great since coins aren't being dumped on the market directly or shortly after, but they could end up with a bad taste in their mouth seeing the value plummet to bottom levels. Stores are mostly just interested in potential sales and to get fiat in return that they can directly use to buy stock or whatever else they need for their store.