Complaint Review: hccost

TL;DR: Ordered a vent hood. Seller shipped an incomplete set of the wrong type of vent hood. Took 2 months and about 20 emails to get a refund. Everything that could go wrong, did.

Aug 24: Ordered vent hood for my kitchen via hccost, a third-party seller on Amazon. My credit card is charged $565.98, and Amazon sends me a confirmation saying the item will be delivered between Aug 28 and Sep 2.
Aug 27: Order has not even shipped yet, so I send an email to the seller.
Aug 28: Order ships.
Sep 2: Item arrives.
Sep 19: I noticed that the box contains the vent hood fan components, but not the large glass canopy. Several mounting components are also missing. As a result, I can't actually install the unit. (It took 17 days to notice because my contractors were working on other things at the time, and had just gotten around to the vent hood.) I sent an email to seller.
Sep 21: Seller responds asking for serial number. I sent it.
Sep 24: Seller says parts have shipped and to allow 7-10 days for delivery.
Sep 28: I request a tracking number.
Sep 29: Seller responds saying a tracking number has been requested and will update me when it's available.
Oct 4 (the 10th day since parts were supposedly shipped): I ask again for a tracking number. No response from seller.
Oct 6: I ask again for a tracking number and threaten to dispute the charge with my credit card company.
Oct 7: Seller says the parts will really be shipped in the next 1-2 days.
Oct 10: I ask yet again for a tracking number.
Oct 13: Tracking info provided. It was shipped on Oct 12.
Oct 14: Parts arrive. The glass canopy is much smaller than the item I paid for. Upon closer inspection of the serial number, I found that the original shipment was also for the wrong size. I am tired of dealing with the seller at this point and request to return all the parts for a refund.
Oct 15: I remind the seller that my only recourse at this point is a dispute with my credit card company if they do not respond in a timely manner.
Oct 16: Seller responds saying they will arrange for UPS to pick up the items. Note: this email was the only email in this entire frustrating experience that contained any semblance of an apology. ("I am sorry I didn’t notice the wrong unit was sent.") I asked to schedule the pickup around Oct 23 because I needed a few days to have my contractors dismount the partially-mounted vent hood. Seller responds saying pick-up is scheduled for Oct 22 and, if necessary, UPS will try again on Oct 23.
Oct 19: UPS shows up at my door saying they'll try again on Oct 20 and 21 but then will give up. I asked seller to reschedule the pickup.
Oct 20 (Tuesday): Seller responds: "UPS is aware and should be coming on Thursday or Friday to do the pickup."
Oct 20, 21: UPS comes two more times and says they will not return.
Oct 23: Seller says they will contact me when pickup has been rescheduled.
Oct 26: I ask seller if pickup has been rescheduled.
Oct 27: Seller reschedules pickup and gives me two prepaid tracking numbers for the return shipments.
Nov 4: UPS tracking shows items as being successfully returned.
Nov 5: I emailed seller to ask about the tracking status. No response.
Nov 9: I remind seller that items have been returned and that I am still waiting for a response. I yet again threaten disputing with my credit card company. It's a recurring theme that this is the only line that consistently gets a response from them.
Nov 10: "Thank you for your email, Your account has been processed you will see the funds back into your account with in the next 3-5 days."
Nov 17: I open a dispute with my credit card company because no refund has appeared. CC company requests that I give seller two more days. I inform seller.
Nov 18: I receive an email from Amazon (not hccost) stating that a refund has been processed. Seller doesn't even bother to write an email to me.