Seller sent return label, seller claims item was delivered and sent my original tracking number

[fairpromise]

So in my previous thread I stated that I requested for an exchange after the seller offered either an exchange, keep for 20% or full refund, but the tracking shows the item was undeliverable due to not being able to reach the facility. I messaged the seller and asked if instead of an exchange to please just issue a refund once the item is in hand. They sent me a return label via Ebay/Email and this process has been taking a very long time, beyond what I initially thought. The item arrived used/opened and I sent it back because it is a perfume and is not really cheap. The seller today messaged me and claims the item was already delivered, sending me my original tracking number. What?? I assume they are either confused or trying to scam me out of the item and money. I am currently waiting for their message. I sent the item back, but should have involved Ebay. I was trying to be a nice buyer and give the seller a chance to resolve things without Ebay stepping in. What should I do from here? 

[martin2001]

If it is within the 30 days window of the sale, file an Item Not Received Case and follow ebay instructions, presuming that the tracking number still shows it was not delivered. Communicate with the seller only thru the case and only when requested by ebay.

[myboardid]

You already returned it so open a return case and enter the tracking number on the return label.