Upon Importing my decks were split?

On upgrading to anking v6 my decks were split to 2 anking decks and this issue continued with the V7 update

There is probably some subtle difference like a trailing space in one of them. Recent Anki versions should strip it, so reverting to a backup, updating and then trying again may resolve the issue.

There is no way for to revert it back to a version without this issue? is there another way to fix this problem without doing that ?

I’m not sure what you’re asking. You can revert back to a previous version using a backup: https://faqs.ankiweb.net/restoring-an-automatic-backup-recovering-from-data-loss.html

If you have made a lot of changes since the import and do not want to update, then you can manually move the decks and cards around into the structure you want.