I'm Disgusted. Shark Cordless Stik-Vac

I have been had, tricked, used, abused, taken advantage of, cheated, and defrauded. I am upset with Sears (not the first time), and disgusted with Shark.  A couple months ago I purchased the Shark Cordless Stik Vak for $80 from a little boy at Sears who assured me he knew all about the housework woes of the common housewife. I was not even slightly convinced that he knew a single thing about the products he was selling, but I have several Shark products that I have been happy with so I bought another. For two months I have been very happy with my vacuum. It picks up everything from hard boiled eggs to cat hair. It's lightweight and easy to handle. But all of the sudden the battery died. After two months, it would no longer charge. I found my owner's manual and found in small print that the battery might need to be replaced every three months. I have been looking everywhere for a new battery and cannot find any place that carries them. I went back to Sears and they no longer carry that vacuum. They can't help me. I went to a vacuum store, and found out that they can order the battery for me, but they told me it's not worth the money and that I should just get another vacuum. Of course, I thought, they just want me to buy another vacuum from THEM. So I check out Shark's website for battery reordering. The battery with shipping will cost me $50. FIFTY DOLLARS! EVERY TWO MONTHS!! You can see from the math, that it clearly isn't worth it. Now I have to buy a new vacuum. And I WILL NOT BE PURCHASING ANOTHER SHARK VACUUM !! I am extremely disappointed with Shark, disgusted. And I would advise anyone to be very careful about any Shark purchases in the future.