Product: Money transfer, virtual currency, or money service

Hello, good afternoon my name is XXXX XXXX and I really need you guys help. I have been scammed by a buyer on PayPal and Paypal literally lied to cover their mistakes! I have all the proof. 

I've had a PayPal account for over XXXX years now. I've never had any problems with my account or anything. About a month ago I sold the phone to someone named XXXX XXXX ( the scammer ) on XX/XX/XXXX through paypal goods and service and everything went smooth without any problems. He thanked me for selling him the phone and everything. And everything was Completly fine. The payment was even held by PayPal to be sure that the transaction was 100 % legit and not a fraudulent or scam transaction. 
I contacted Paypal in regards to this transaction and was told to wait XXXX hours at first and then after there's XXXX hours had to passed and the money was still being held by PayPal. I was told to wait another XXXX hours, then which the money was taken off of hold on XX/XX/XXXX. Again everything was working without any problems. I didn't have any negative balance, or any cases opened or anything like that. So yesterday XX/XX/XXXX I logged into my PayPal account and I see that my account is negative for the amount that I sold the phone for plus the fee. And I'm so confused as to why my account is negative because I haven't done anything wrong with my account. So I contacted PayPal customer support and I was told that the buyer ( XXXX XXXX ) had filed a dispute on what Paypal is saying, the same day that I had the money released. Which is really weird. Because like I told you guys, I literally didn't have any cases opened or anything when I logged in that day to withdraw the money that I had on there from doing the sale. This is a vital point in this because I have proof that they are literally lying. So to continue I was told on XX/XX/XXXX when I noticed that my account was negative that they had been emailing me since the dispute was opened which is a lie and since I did not reply to the emails and the attempted contacts from Paypal they close the dispute in the buyers favor on XX/XX/XXXX. Which is literally XXXX days ago. I checked my email because I told them I had never received any dispute or emails from PayPal because why would I not reply to someone trying to scam me. Of course I would've followed up on the dispute. Upon checking my email there are no emails in my inbox from Paypal regarding the situation. So I dug deeper and I checked my spam and I see that they emailed me not on XX/XX/XXXX when they claimed to have done so. When the buyer opened the dispute against me. The emails clearly show that they did not email me until. XX/XX/XXXX for saying that the case has been opened keep in mind. All of this is in my spam folder. I've never in the XXXX years of me using PayPal had any PayPal messages go to my spam folder but now, all of a sudden, after I've gotten a dispute filed against me now they're going to my spam folder? That's also super fishy to me. XX/XX/XXXX is the only time I received any type of correspondence from Paypal in regards to this case, they did not follow up or anything. So they are lying about saying that they have been emailing me about this case. I literally just want my account back in good standings because I didn't do anything wrong! And now I have XXXX in my account, which is why I even checked my account on XX/XX/XXXX is because I had received a XXXX transaction how do I not receive that transaction I wouldn't even known that my account was negative. I didn't get any follow up email saying I have a negative balance or anything I had no idea any of this was even going on. I have all the proof and you guys can clearly see that the timelines they are giving me are completely off from what really happened! They basically let this guy scam me without any consequences or anything and now they're saying I have to pay my balance in order to get my crypto, which is completely unfair!