Hello everyone,
I allow myself to come and make a post here and having sent an email to the support, I hope they will answer me because I admit to being in a panic, I explain it:
A few months ago, I bought several assets with the plans to modify them at my convenience and publish them on the store, so I downloaded them and until today, I wanted to rework on the current game to make updates on it, and there the big surprise! I go to the packet Manager to be able to download the asset, and there is nothing left, so being in a panic, I go to my unity asset account, and all my purchased assets are no longer visible, therefore untraceable, I can no longer download them! 
I even lost my list that I made for other assets, but for that, it does not matter at all.
Regarding the order page, there is nothing left either, knowing that I have indeed purchased assets (to be seen with support, but if they want, I can send them my bank statement)…
And at the level of my account, I have indeed connected with the account where I made my purchases.
So I sent a message to support, but do you think they will be lenient and accommodating? Because I am completely blocked on my project, I no longer have access to my assets, and therefore do not want to pay a second time!
Still in a panic, according to support will they be able to send me the download links of my purchased assets? Because if it is not possible, I am really pissed off.
Have you already had this problem, if so what did you do to download your assets that are no longer visible?
Thank you to all those who will answer me and reassure me.
Antoine