Product: Checking or savings account

Purchased bag on XX/XX/XXXX I purchased a XXXX XXXX backs pack on XXXX for the amount of {$1100.00}. The package said it was delivered on XX/XX/XXXX. I never received the package even though it said it was delivered so I checked with my neighbors and no luck. I contacted XXXX on XX/XX/XXXX letting them know the package was missing they told me to wait until the end of the day to see if the package shows up and if not they would make sure I was compensated. I contacted them back on XX/XX/XXXX letting them know the package still did not arrive they told me to follow up with the post office and to get an intranet report. They told me I could get it from any post office as I asked since I was out of town. I went to the post office where I was at and was told they can only pull that report at my local post office that delivers to my house. I came back in town and they were able to print out the report but were unable to give it out to a customer ( per the Postmaster ) I contacted XXXX back and they said they were sorry the package was still missing and to keep following up with the post office and that the transaction was completed ( without my authorization ). The post office was able to locate my package on XX/XX/XXXX and when I opened the package it was a completely different bag. A XXXX XXXX bag probably worth {$20.00} nothing compared to what I ordered a XXXX XXXX bag. I contacted XXXX letting them know of the issue and they refused to let me return it saying it was past the return period. However it was not my fault the package was lost and when I received it it was not as described also they made me wait a full 3 days ( past their return period ) just to see if the package would arrive as they said it could have been a mistake with the post office. I opened up a dispute with my bank and they denied my dispute because the mercari return policy is 3 days from recieving the package even though I provided proof that XXXX made me wait a full 3 days to see if the package arrived and it didnt. I contacted XXXX within the 3 day period letting them know the package was missing so how can I return something I never recieved. Their buyer protection guarantees the buyer to be eligible for return or refund if an item is missing or not as described and I let them XXXX know of the issue as soon as possible which was before the return period ended. After days of contacting XXXX back and forth they say that they had to complete the transaction since the tracking said delivered and there was nothing they could do. If that was the case then why even make me go through the trouble of providing info to them if they have to accept the transaction since the tracking shows delivered. XXXX has now suspended my account for opening up a bank dispute and now have deleted my account so I cant even contact them at this point. Ive tried contacting them multiple times by phone on hold for hours waiting for someone to pick up and was told by the representative that I could not speak with a supervisor as they only contact via messages and do not speak on the phone. Its unfair because XXXX claims I accepted the package and rated the seller but XXXX accepted/rated and completed the transaction automatically on their end which it states in the messages attached. I let XXXX know before the three days were up of the issue with the package missing and now that the package arrived late on XX/XX/XXXX Ive been scammed out of my money. My bank advised me to return the backpack and I have done so and have heard nothing from XXXX.