$1,000,000 credit (i am not joking)

I have discovered an interesting quirk with a Netwealth trading account....I hope they fix this.

If you have for instance $25,000 in your trading account and place a buy order on a stock and you do not get a total fill, ie say you only get $20,000 of the particular stock, you can then cancel the trade but you will keep your $20,000 of stock.

Now go and buy more stock, You think that your available credit is only $5,000 right? Noooooooo its not, you still have $25,000 to spend. You can do do this all day as long as you close out your position before end of trade.

I hope all the risky daytraders don't find out about this.