Fedex Prepaid Labels for Textbooks Issues

[applesxoranges, BSN, RN]

Has anyone ever encountered a store trying to upsell filler if you use prepaid shipping labels? I've never encountered it before but I usually end up with USPS or UPS shipping labels from the providers. The Fedex store I went to today tried to sell me filler for four bucks otherwise I had to go home to ship it (this is after shaking the package). I went to the corporate store that only does shipping next to their warehouse and they took the package no issue. No shakes there.

I googled that store and the review had a negative one complaining about the upsell for filler when using prepaid labels. The reviewer said his business used prepaid labels. A handful of other stores also have negative reviews about stores upselling fillers or packaging throughout the country.

UPS and USPS have never told me that I needed to pack anything in the boxes or bags when shipping back textbooks.