hey guys my ute's battery gets flat over time and its a good battery fairly new and new alternator wat else can it be?

How long a time?
If the storage device [battery] and the charging system [alternator and regulator] are working correctly, the only other thing that can flatten a battery is a continuous load.
Do you have an Alarm connected all the time?
Do you have a Amplifier or Head Unit which requires constant power for memory etc?
Alternatively, there may be a fault causing a continuous draw on the battery.
To test you can do: -
1. disconnect the battery when you aren't using the car.
When you next need to start it, the battery should be fresh as a daisy.
If not, it is self discharging and therefore faulty.
2. measure any current draw from the battery terminal when everything is turned off.
Use a multimeter set to measure current.
Connect it in series with the earth cable to measure the exact draw or use a 12V test lamp in series with the earth cable to indicate the presence of a draw.
If there is a draw, you need to isolate the cause.
The easiest way to do that is to start pulling individual 12V fuses and see if/when the device used in 2 above signals no draw.
A faulty Voltage Regulator can cause the battery to discharge over time.
That can only be prevented by disconnecting the battery terminal[s].
If you suspect the draw is via the Voltage Regulator, no option but to replace it.