Online shopping

I received a gift card for my birthday and decided to use it on groceries. i placed the order online and i paid with the gift card. ONLY problem is that i haven't received an order confirmation and when i tried to inquire about this. The money is off from the gift card. i have sent numerous emails but no avail. Please get back to me ASAP as now i don't have the money on the gift card and don't have groceries?