usa.etowine.com review for QD (Quantity Breaks/Discounts)

After an initial flurry to customise the app for our store, which seemed helpful (which is why this review is 2 starts not 1), customer support became ridiculously slow, and actually caused us to lose sales. The app caused a malfunction in cart - showing cart empty. QD did not announce when they were working on the site which adversely affected our customers, too. We have had no response over a week after telling them about the malfunction so have now have deleted the app.