Compression Sales Compression Sport Sent wrong product, tried to blow me off x2, then agreed to exchange and pay shipping, then charged me for shipping Internet

I ordered McDavid compression sleeve model #8836.  I received model# 6572.  I sent an email regarding this and got no reply in 2 weeks so I called them.  The rep stated the 6572 is the replacement for it and the newer version.  I looked on their website and the 6572 was a cheaper item.  I called the manfacturer McDavid and they stated  it is not the same product and that 8836, the product I ordered, is the better product.  I emailed Compression sport back with that info and was told they don't know who I spoke to at their company but they  are different products and that I had ordered the 6572 model number and I should have caught that I ordered the wrong item on my email.  I looked at my email and it clearly shows Mcdavid model #8836 like I ordered, however, it also shows Compression sport item #as 6572 which I understood to be their internal number since it showed model #8836 as the actual product model #.  I replied with screenshots to prove I ordered #8836.  They apologized, said it was their website error and they would fix the website as I clearly had ordered #8836.  They stated they would exchange it and they would cover the cost of reshipping.  I received another email from them with a return authorization that stated they would cover the cost of reshipping in the return authorization.  2 weeks after receiving the product they hadn't sent me anything so I emailed them a reply to the return authorization.  Their response was that they will ship it today and had charged me $6.95 to reship, even though that very same email had the email string from them stating they would pay the reshipping.  I replied that I shouldn't have to pay that since it was their error in shipping me the wrong product and that I had 2 emails stating they would cover the cost of the reshipping.  This was a horrendous experience and probably commonplace for them.  Additionally, I shouldn't have even had to pay to ship the wrong product back to them in the first place but did so anyway and now they've charged my credit card without my permission $6.95.  I will keep fighting this but shouldn't have to.  I wonder how many others this happen to that don't do anything about it.