Curve 9360 Reporting Incorrect Battery Life

I have a Curve 9360 with the latest 7.1 OS (Updating didn't solve my problem).

Problem I'm having is that the phone does not report the correct amount of battery life remaining. I've tried running it till it's completely flat and charging it overnight to make sure it had a "full" charge but within 30-60 minutes of use it shows that the battery life has dropped from 100% to 1%.

I can use the phone for hours at 1% till it actually dies. Like yesterday, unplugged from the charger at 6am, by 7am it said the battery was on 1%, battery had only really run flat at 9pm. I've tried enabling and disabling the power saving feature but it didn't make a difference.

Is this a fault with the device itself or the battery? I don't have another battery to test unfortunately. Will this issue be covered under warranty? If so, how long would it take to get swapped out or repaired (Vodacom)?

How old is the phone?

6/7 months.

Edit

6 months end of June

Sounds like the battery, I've seen this before. Borrow someone's battery for a little while to verify.

I'd get my hands on a new/different battery and see if that helps. If it's not the battery then prepare yourself to be without a phone for a few weeks while it sits on a table somewhere until they eventually get around to swapping it out with a refurb unit.

This is odd but it seems like the BlackBerry Protect app is to blame (Didn't mention installing it as I didn't think it mattered). They released an update for it 2 days ago (I think, well I saw that an update for it was available 2 days ago) and after updating it and rebooting the phone it's reporting the correct amount of battery life remaining.