The Whyalla Salvation Army was named Business of the Month by the Chamber of Commerce and Industry.
Store manager Kerri Morris said she was absolutely shocked to have won.
Mrs Morris said previously, members of her staff had been nominated for the customer service of the year award.
She said winning the award and being nominated by her customers was “really rewarding”.
“I’m a bit overwhelmed and a bit speechless but I’m really proud of me and my team,” Mrs Morris said.
“I didn’t know anything about this [award] and they rang this morning, so it was a nice surprise.”