I have very little experience with returning my online purchases. I recently purchased a pair off the shelf SS exhaust tapered transitions. It not important at this time their name, it is a well known vendor.
The transitions were approx $80 ea, they were in stock, I paid by credit card, they were pictured in their offering, but it is understood by me pics are often only representative, they were shipped by my choosing US priority (2-3 day) mail from Calif to Florida in a "if it fits, it ships" box, for $32. They arrived in 6 days, and they had an abrupt IMO transition going from 2.5"D to 3" Oval, which for my application/use defeated the whole purpose. I called them, and my opening comment was to the effect, "you sent me what I ordered, but its not really what I wanted or thought the pic represented". They replied basically in my words, "Oh Well". 5 days later I called and said I'd like to return them. They said there is a restocking fee, which in this case is not exciting, and its in the fine print, and they can decide what the real cost of restocking is vs the potential loss of a future disappointed customer. So I shipped the transitions back, same method as I received them, and PO charges me $15.05. Additional fine print from vendor says there is a 3% fee of credit card restocking purchases.

So is a 25% restocking fee normal in the above?
Does the 25% fee apply to the doubled? shipping cost?
Is it normal to more then double the USPS shipping cost?
Does the 3% Credit card fee also apply to the shipping cost?
I hope I haven't put too much Spin on this, and included enough Tech that is appropriate to get a heads up on what to expect.