Blackberry Bold 9780 - problem, need help.

Hi there, i have several problems with my blackberry and i would like to know if they are interlinked and if i can do anything to fix the problem.
My blackberry:
1)Turns off when the battery is at 50%
2)When 3+ minutes into a call, randomly cuts off and says 'call failed'
3)Randomly displays a white screen and nothing can be done but when reboot it is fine?
4)Sometimes freezes, whereby the 'ALT' and 'shift' button work and display in the top right corner however the phone itself does not work
I have been told it may be the trackpad or the battery if this helps?
I have tried wiping my phone, updating the OS, battery pull etc etc.
Thank you in advance.

I forgot to mention, it is on os 6.0
v6.0.668

Hello,

The phone turning off at 50%, I'm quite sure that it's because it's not a genuine battery, I bet it's one from China. Has this problem before with 3 batteries that I bought on Amazon, had to buy a brand name and things are cool now.
As for the other problems, I'm sorry but I have no idea :(

The battery is genuine; Ms-1
tbh its mainly the freezing that agitates me

I use .666 which is pretty close to yours. Never seen a freeze. Ever.

What apps do you have? Do you check these for updates? (Easiest to do via Blackberry Desktop Manager on the PC)

Have you checked your memory card is still okay? Is it a quality brand name like SanDisk? Again, you can make use of a PC. Plug the phone into the PC and select USB Mode. Then perform a check disk on the memory card to check for errors. Maybe even try out a different memory card for a bit.

Did you buy the battery from a reputable seller, or is it an original battery? Anyone can stamp a battery with MS-1 and call it genuine.

Also, keep in mind, if you've had this phone for a long time now and have always had this battery, it could be dying.