Kenneth, you only have 7.47 mb free. I am actually not surprised you are losing logs and messages, and would have predicted it, knowing the file free, had you asked ahead of the time.
You say you have read all the threads about what to do, so here you go again...
Why is my BlackBerry losing its call logs or message logs? - BlackBerryFAQ
How do I free up memory on my device? - BlackBerryFAQ
My suggestion: First, pull your battery and reboot your BB. Check your file free again (should be over 10mb), then read and follow the many instructions in those links I gave you. You will be shooting to get upwards of 15-16 mb file free. While there is no magic number, that seems to be a good place to be. I have seen some lose logs at 22-25 mb file free, but it is rarer.
Then, about 1x a week, while your BB is powered on, pull the battery on your BB and let it reboot.
Do you have a Micro SD card? You need one.
Meanwhile, if you still disagree that this is not your problem, and that your memory is excellent, I don't know what anyone on here will tell you to make you happy. Follow those instructions above, and you will be.
You didn't answer whether you have a backup or not, hopefully so. Let us know, there is a way to get your call logs from a backup.