i've never completed the battle squares before today. but all i got in the first few levels was bolts and darts and after about level 3, i never got anything. i figured there would be some sort of grand prize at the end but there isn't. i completed seven blocks of each rank so i dont know what went wrong. i know (after checking here) that i was supposed to recieve some items. any ideas?

You have to do more than just do 7 blocks for each rank. For EACH rank you must complete the game having 3 then 4 then 5 then 6 then 7 blocks covered. In other words you must play each rank 5 times. (but the order does not count - you can do 3,7,4,6,5 or whatever, just do them all)
The online guide here at SP shows what the prizes are:
http://www.sorcerers.net/Games/IWD2/Walkthrough/chapter2/area3.php

oh my sole. thats no joke. ok cool thanks i'll get it done. already did the hard part i guess...

It's kinda like pulling teeth. If you know you can complete it (I make sure I manually do each hardest level with 7 squares), I use EoU's "skip battlesquares"

Just throw out the extra treasure to be fair.