Are you joking? Is this "As My Mail Order Turns?" I thought you had sent it back by now.
Look on your invoice or packing slip. (The paper that came with your order). It should describe a return policy, such as return within 30 days for a full refund.
Just pack it up. Mail it. And demand that company pay the postage. Stop being such a wimp. They don't care how you feel, and they don't care if the pills are moldy! Just get your money back, that's all.