Hi!
We're sorry to hear you are having this issue. You can find the game saves on the PC where you played the game, under the follwing path:
C:\Users\<user name>\AppData\LocalLow\Xaloc/LOL\
Depending on how you lost them, there are several ways to recover your lost saves explained at the following link: https://www.easeus.com/file-recovery/recover-deleted-game-files-on-pc.html
We hope you find this helpful.
As for DLCs, we haven't heard about anything for the time being, but we will let you know if we hear it is going to happen.
Apologies for the inconvenience.
Thank you :)