I just saw this (months later) and I am sorry it took so long.
During our first 6 years we always had same day shipping if it was in stock. However we have been fighting a constant battle to stay on the same day for the last 6 years. It has been growth, our growth has surpassed all of our estimates since the very beginning. Certainly a double edged sword. In the last 3 months we have brought in 3 new shippers to speed us up but its not like we haven't been doing that all along. We now have 12 people working in the shipping department and all are now up to speed. We also spent a cubic buttload of money on the best software program out there to aid in inventory control so we will be out of stock less and less.
In our defense, we have never put smaller orders ahead of larger orders, all orders are shipped in the order they are received unless something is out of stock. And when it is out of stock most items take only a couple of days to get back in stock.
We have been shipping same day for the last 10 days and I expect it to continue in the future. At the worst Monday orders may ship Tuesday due to the buildup of weekend orders ahead of them but we will be adding Saturday shiping over the next month to help avoid that too.
Again, I am sorry this happened to you.