Tradesy Release the funds into my account since the buyer has received the goods and Tradesy also got paid Internet

On August 27th, I sold an item on Tradesy and used the shipping label they sent me (printed and prepared for shipping on August 27th 9:30 am) - I placed the package in USPS drop box on August 28th approx 7:45 am.  USPS never registered that the item was recevievd at their facility.  I emailed Tradesy over the weekend to ask them to open a claim since there is no record that I mailed the package, even though I did.  Since I contacted Tradesy I got an email yesterday from the buyer stating that the package was received.  I have since tried to contact Tradesy several times to ask them to release my "payment" to me as the package has been receievd.  No one has followed up or even acknodlegded the multiple attempts to contact them.  I have all of the documenation from both the buyer, USPS (which I filed a claim for them to respond that the package was in fact delivered) and not a work from Tradesy, they got paid for their commission but I am still out both the item and the funds.  I even did all of the leg work for them by contacting USPS and the buyer.

The original Tradesy order # is 920800-1500934B and the USPS tracking #9405510898416002686602. The claim that I filed with USPS is # HQ124520497