Today , the post office I usually use tried to scan the paperback swap printed scan which I paid PBS twenty cents for. They have done it in the past with no problem. Today, when he scanned it, it showed the twenty cents for the merchant scan, but only gave him a choice to charge the ninety cents for the post office scan. He said it was because I was paying at the window, so it didn't classify me as a merchant. He finally did a postage free scan after I paid for the package. This is different, in the past they were given the merchant choice , which they chose, and then they linked the two scans. What is different in the system that it no longer scans PBS tracking as a merchant , already paid for?