What is the point of pending balance taking so long

what is the point of making my balance pend for 3 days when i wanted to get diablo 2, i added balance to my account to buy the game, and now it is saying it is pending for whatever reason. I jsut struggle to see a point to this, couldnt they just give you the money and if they find out it is fraudulent ban your account or reverse the transaction???

I have the same encounter except, the transaction was reversed silently via email. I only realised when I tried to play it just a few hour before the sale end.

I went to check my transaction history, I cannot find any. The email sent to me clearly indicate the transaction is completed.

Now I purchase again, but the transaction show pending. This is so frustrating and disappointing. What happened to Blizzard!