0531 50000 dollars to 500000 dollars

I gave my fiance my cash card of 土地銀行 two weeks ago.I asked him to withdraw 100,000 dollars for me to deposit it to another bank.After it,there should be about 50,000 dollars left in that account.I took my cash card back last weekend.
When I arrived at Taipei MRT station,I used one of my cash cards to withdraw money.However I got confused by these cards.I can not remember all the banks' names well.When I put the card of 合作金庫,I regarded it as the card of土地銀行.After I got my money,I chose to show the left money on the screen.The money should be about 50,000 dollars but it turned out to be 500,000 dollars.I was so surprise that I can not believe what I had seen.I calculated the money again and again and tried hard to figure out what had happened.Did my fiance want to give me a surprise?Why did he deposit so much money in my account?I was so happy that I cannot stop smiling.
When I got my cash card back,I saw the bank's name.It was 合作金庫,which bank I have deposited my salary since I came to FHK and never withdraw it.The 500,000 dollars was my salary.When I figure it out,I laughed myself silly.Being such a frugal person,it is impossible for my fiance to give me money.Let alone such a big amount money.