Upgraded without your consent eh? I think if I were in that situation I'd send the invoice to the merchant and have them pick up the tab.

I ordered a kilt from overseas and had it shipped FedEx. I received a bill for duties, taxes, fees etc. But I knew I was going to be charged these things when I placed the order.

If you chose another method of shipping to specifically avoid FedEx's fees and then had them applied to you because someone thought they were doing you a favor then the guy doing you the favor should foot the bill.