Tax lot on sale of a stock

I had 100 shares of a company stock bought more than one year ago. In December I sold 50 shares of the stock to realize long term capital gains with LIFO. I bought back the 50 shares within 10 minutes of selling them. Now when I look at my account it shows that I bought the shares first in December and then sold the 50 shares making it short term. I think my instructions were correct so why did it treat it this way. Can this be corrected?