Watch out at this post office. The scale at the automated machine is not correctly calibrated and is overstating the weight of mail packages and thus overcharging for postage. I mail DVDs to my online customers on a regular basis and am very familiar with the typical weight (normally around 9 - 11 oz) and postage cost of item. I was surprised therefore when went to use the stamp machine at this post office that the mailing charge was $0.50 to $0.90 more than usual. As there was a long line behind me I went ahead and paid for two packages but then stopped at the third one that said the weight was over 14 oz. I took the remaining packages to Pineville-Matthews post office (where I usually go) and used their automated machine to stamp the remaining packages at the lower (correct) weight and cost. I didn't put the packages in the mail just yet but instead drove back to Ballantyne Post Office and used their automated machine to get the postage cost for the now stamped packages and proved that the machine is overcharging. Once again the scale reported weights around 50% higher. The post office was now closed but I saw a clerk coming out with a large sack of mail, I stopped her and reported the issue to her. She started trying to make all kinds of excuses initially suggesting that maybe I'd made a mistake and then saying that sometimes the machines are 1 ounce or so off but it makes no difference to the mail charge (not true). I explained that I had the evidence from Pineville-Matthews PO with me and the difference on my packages was at least 4 oz and their machine was making a significant overcharge on the mail. I warned the people in line behind me also. I hope the post office takes care of this matter and in the meantime this serves as a warning to other customers to be careful not to get bilked. It is sad that this is occurring during the week leading up to Xmas when the post office is at it's busiest, with hundreds of packages being mailed every day.