My battery used to last at least the entire day when I bought the phone 10/09/2009, less than a year ago, now for example the battery only lasted me today from 9AM to 2PM until it said that it is very low.

I called HTC and they bounced me around. Basically they told me to buy a new battery and not even from them. They stated there is no warranty on the battery, but then I found the warranty card and it states otherwise.

How do I get HTC to replace the battery?