Mylti order shipping after the fact

Description

Hello, I was wondering if anyone had used multi order shipping over the holidays an recently received a notice of under paid postage. My notice says incorrect package dimension. The package dimension i used is exactly what they say the new machine they used measures. More they want to charge me more for the label I printed and used. Anyone else having this issue? They have limited me to no use of multi order shipping until this is resolved. There are actually 3 packages they are disputing. Totalling over $80. The lady at the post office says they attached a service charge on all packages over the holiday season. ( yeah just another way to **bleep** people during the holidays) She is suggesting that pay pal shipping did not access this charge so they are trying to recoup their losses.