To clarify, any visuals saved to an account using the manual Save button from the upper menu should appear in the Dashboard. If the saving process completed fully, your work will be visible there. Unfortunately, any versions not found there did not successfully save and are no longer available. We cannot retrieve a lost Piktochart or one that has been deleted. To clarify, we never delete any user's saved content.
We have on occasion discovered that a Piktochart user may have created two Piktochart accounts, and sometimes the visual in question is actually located on the second account instead. This may not apply in your situation, but we do like to mention the possibility.