Poor Service from Netflorist

I am extremely disappointed with Netflorist. I placed an order only to be told a few days later that the item is out of stock. They then issued me with a voucher so that I could choose another gift. After receiving the voucher and selecting another gift, I was told a day later that this item is also out of stock. I understand that these are exceptional times, with COVID 19 at large - however why is the order processed and accepted when there is no stock?