I am curious how did you settle this issue. I was recently charged by Shopify for a USPS shipping adjustment where I shipped a 6 oz package and Shopify says it was USPS determined it was 175 ounces which is impossible. I checked my bank account and found since April they had deducted $2,597.00 from my account in bogus shipping adjustment fees. I brought it to their attention over a month ago and still nothing has been refunded. Each time I ask I am blown off or even the same story that they had USPS open an investigation.
I am dealing with the same issue they charged me over $2000 in bogus Shipping Adjustment fees trying to tell me a 6 oz tshirt in a small poly mailer did not weigh 6 ounces but USPS said it weighed 175 ounces who ever heard of what would be equivalent to an 11-pound T-shirt. I am thinking of suing of starting a class-action lawsuit seeking exemplary and punitive damages
I am dealing with this madness now they charged me 152 times for Shipping Adjustment Fees to the tune of over $2500 dollars. I brought it to their attention and they are doing nothing. I am in Las Vegas Nevada who did you contact but I am getting nowhere with Shopify Support or Shipping department and it's been over a month since they claimed they had USPS investigate the issue butr are waiting to hear back which is total bs . I am thinking of getting an attorney
Just to give everyone an update on this issue. I had a conversation with my new FedEx rep about the adjusted pricing and Shopify. She could only speak for UPS and FedEx, but every package that goes through their distro facilities is measured with a laser scanner and weighed accordingly. The laser scanner will pick up even the smallest variances in dimension and adjust to the carrier's favor (I don't know what the threshold is but would assume it to be inches. So, if your package is 12x12x12 and it's bulging because of the way that it is packed by an inch, the new dim is 12x13x12 and will be adjusted as such. She said this is the case even with soft packaging. If the corners are sticking out and you haven't accounted for that in the shipping dimensions, the price will be adjusted. Seeing as UPS and FedEx employ dimensional weight rules, the adjustment can get pretty pricy. Anyway, that's the scoop from the pros.