Today I opened sgd/jpy short position with take profit at 75.319 and when I checked sgd/jpy from MT4 it already hit 75.319 its last low was 75.306 but my position did not close. I opened sgd/jpy chart from jforex platform and I saw that it could not download the latest data of sgd/jpy.

Be carefull if you use MetaTrader. It shows only historical BID prices on the chart and there is no way to get the historical spread at that moment. In your case, the Take profit is a buy order and the ASK prices should be investigated.

The market has its demand (orders with amount on the buy side) and supply (orders with amount on the sell side). If the best offer hits the Take Profit level, or even goes lower as in this case, it does not mean that every order at this level would be filled. There might be other orders in the queue before yours, which might get filled. If the order would have been placed as Place BID, it would be shown in the market depth and the best offer could not go lower than your level without the order being executed.