MISSING ITEM in OPENED TAKEALOT BOX!

I ordered a PAIR of PINK teething mittens and when it was delivered, the box was opened upon delivery and only ONE ORANGE teething mitten was inside. I did not take delivery of it, as I would of not accepted but it was left without explanation. I called customer relations and was told Deals Galore, their supplier has no stock, so if I want a PAIR of mittens I must return the order and pay an extra amount to purchase it from a different supplier. Alternatively I can return it for a credit. I find this resolve pathetic, as I am at a disadvantage in both scenarios. If your supplier was out of stock why was the purchase successful? Why have I received ONE mitten in an opened box? I called customer relations this morning and am still waiting on a senior staff member to call me back.