Stole Money Can t get money for a completed order

How to Report a Dispute
Please fill out all 9 questions below. You must provide proof or your claim cannot be validated.

1. Date Dispute Happened
September 15, 2021

2. Are You The Buyer or Seller
I'm the Seller

3. Total Transaction Value
$150 USD

4. Other Parties Username
User15799, Middleman

5. Method Used To Pay or Receive Payment
Bitcoin

6. Other Parties Email Addresses
I do not know (https://www.playerup.com/user15799, https://www.playerup.com/middleman)

7. Other Parties Payment Email Address
I do not know

8. Other Parties Messenger Username
---

9. Provide All Chat Logs and Additional Information Below
Basically, I am the Seller. The sell was made via Middleman service. Both Seller (me) and Buyer (User15799) have confirmed that the order had been completed by setting the corresponding statuses (Seller - Confirms Delivery; Buyer - Confirms Delivery) in a 3 way conversation: https://www.playerup.com/conversati...-id-wo_z2u4ptbwmw-3-way-conversation.2253419/
I've requested the payment a bunch of times - and did it according to the guides on the current website. The trade has been completed on August 10, 2021 and I'm still unable to get paid.
I've tried to reach Middleman a bunch of times as well - both in a 3way conversation and in a private conversation. They just ignore me. I also tried changing the status of a 3way conversation to "Need MM assistance" - nothing. Such a poor service. Almost a month have passed and not a single word from the @Middleman service.

I do not know what is the proper next step should be to get the money.
Please help.

Best regards.