Web shopping has pros & cons. The pro is that it is relatively easy and the pay pretty good for what you have to do.
The cons: Any hiccup and you end up spending hours trying to get it resolved with the vendor, you are pretty much on your own to get it resolved (you take on the risk not the MSC). I got to the point twice where I was ready to call my credit card company (against the request of the MSC because they couldn't use my shop if I did) because I was left holding "the bag" (charge on my card for a returned item & bill coming due); luckily the vendor finally came through.
The other con is you have to look closely at who pays the return shipping. This caught me by surprise, I thought every seller on the platform was the same (they pay); needless to say you have to front the shipping costs (which aren't cheap) to return items and WAIT & WAIT for reimbursement.
Other note on returns - ALWAYS, ALWAYS, ALWAYS use the label provided by the shopping platform's return process, not a label provided by the vendor in the package. By using a return label outside the platform, you're pretty much on your own if the package gets lost or severely delayed (learned that one the hard way). Burden of proof is on you. Another ALWAYS - get a receipt when dropping off the package, especially USPS who is notorious for losing packages.