When you silence the battery, that only kills it for 24 hours.
The alarm can be silenced for 24 hours by pushing and holding the blue button on the front of the power supply for three seconds.
Sometimes it's a false negative so check by unplugging the AC power, disconnect th ebattery, and leave it disconnected two minutes, and then put it back together. If it stops beeping then it was just a false negative.
Otherwise you legitmately need a new battery
If you expect someone to replace your battery on principle, then I don't know what to tell ya. ALL battery's have warranty's, the TOS explicitly states how long the battery warranty is.
Do I wish they would replace it, sure.
Is it worth 12 dollars and a little elbow grease to avoid having a coronary and having to wait on hold with Customer service? I think so.