I am sorry but what you were doing was, cleary, ilegal in some countries (I guess in Taiwan too). In this case the shop must keep the initial price (even if it is an error) and honor the price. This is basically done so it can not be use as a "marketing technique", when shop use very competitive prices and then, later, it modifies the price to already sold items.
Regards,
I had to check the relevant laws in Britain quite recently. The situation is: When a seller offers a product for a price, he is under no obligation to sell it to you at that price, and under no obligation to sell it to you at all. That would cover the case where the seller by accident marked an item too cheap.
However, if you believe that this was done intentionally to get you into a shop based on a low price offer, trying to sell you stuff at a higher price, then you can call trading standards on them, and they _will_ do something about it. That would obviously be the case if Apple offered a MBP for $199, then told you it was actually £999, and then didn't change the price tag. If it was a mistake and they are fixing the mistake, there's nothing you can do.