Instruct: Classify the given review as either positive or negative.
Query: New formula - Yuk!

Unbeknownst to me, the new formula was shipped to me. I used to love this stuff. It worked great and tasted palatable. I usually use less powder than what they recommend since I need a lot more water than other people. Now they've used stevia as the sweetening agent and the product is bitter and nasty tasting. It was so bad I thought the batch was off and was going to return it as defective! Then I saw the mention of stevia on the label. Oh...that explains it. That stuff doesn't taste sweet at all. It's worse than old school saccharin. Also they lowered the amount of calcium and changed other ingredients. It sounds like they reformulated to reduce costs. I can't use this rubbish. I want my money back and I'll have to try something else.