Product: Money transfer, virtual currency, or money service

While selling a daybed, for {$250.00} on offer up, an online app where you are able to sell your belongings, a man named XXXX responded to my ad, showing interest. We exchanged phone numbers and he explained to me that he would not be able to pick up the daybed himself, and that he'd send extra money for his furniture movers to pick up the day bed. We agreed to a negotiating price of {$230.00} for the day bed, and I agreed to receive payment in the form of a check, which would be payment for myself, and for the movers I'd be able to pay in person. XXXX 's accountant emailed me the check, along with instructions on how to deposit the check. After opening the email, I saw the check was for {$800.00}, so I knew {$230.00} was for me, and {$570.00} for the movers. I only agreed to pay the movers if I could swipe my card, so that I'd be better protected, rather than handing the movers cash. After the check was completely deposited, XXXX told me I'd have to set up the appointment for the movers to come myself, as they do not show up unless appointments are made online. I told XXXX I'd feel better about him setting up the appointment, with his own credentials, as the movers would not come unless payments were made in advance. XXXX agreed to have his {$570.00} sent back, and gave me a XXXX  user account to send the money to ; XXXX XXXX : XXXX. I called my bank, Navy Federal Credit Union, in order to verify the check was completely deposited and that there would be no way for XXXX to take his check back. The representative said the check was completely cleared and deposited, and also told me if I sent money back to XXXX, I'd still be protected by Navy Federal. I sent the {$570.00} to the XXXX account, and XXXX claimed to have never received the money back. At this point, I decided I wanted to be done doing business with him, and asked him if I could send back the rest of his money so that we could both be done. He sent me his brother 's XXXX account : XXXX XXXX : XXXX. Once again, I called Navy Federal to double check that there would be no way for the deposited check to be pulled from my account and that I'd be protected if anything were to go wrong, and they confirmed I would be. I sent the money, and thought we'd be done with business. On Tuesday, XX/XX/2020, I woke up and realized the check that was supposedly completely deposited into my account, was withdrawn, and now I was missing the initial {$800.00} XXXX sent to me, in addition to the {$800.00} I had to send back to XXXX. Upon research, I found that the " fake check '' scam is something used often by scammers to essentially steal money. I called Navy Federal again to file a complaint, and also receive the money they said I'd recieve back because of their " protection '', but all they could do was offer a dispute for the transactions, and told me there would be a very slim possibility of receiving my money back. I faxed in documents to Navy Fed to prove I was being scammed. I called XXXX, but they would not give me any information as to who was behind the two XXXX  accounts I sent the {$570.00} and {$230.00} to, and only kept trying to redirect me back to a Navy Federal representative, which already proved to be unhelpful. After reaching dead ends with both companies, and being ignored by XXXX, I filed a police report with the XXXX XXXX County Police Department, in XXXX, VA, against the scammer. After sending in my proof, all Navy Federal Credit Union could tell me was to just wait for their security team to finish the investigation. On XX/XX/2020, I received a letter in the mail, from Navy Federal Credit Union, informing me the dispute has come to the conclusion that there was nothing done wrong on Navy Federals end, and that I am completely responsible for the {$800.00} that was lost. I disagree that I am responsible for my loss, because I would not have made the {$800.00} transfer if the representatives I spoke with, from Navy Federal, did not say there is no way the deposited check can be pulled from your account. I called Navy Federal at least 3 or 4 times the weekend the transfers were made in order to confirm that the check was completely deposited and that Id be protected in the event of a scam, and now after all is said and done, I am responsible for the money the representatives told me the scammer couldnt pull from my account.