Unfortunately, many money transfer apps do not offer protection against stolen money, especially in a case where you've given your login information or your 2FA code out willingly. If you've had money stolen from the balance in your Cash App or Venmo account, there isn't much you can do to retrieve your money.
If the scammer steals money from the bank account or credit card that is linked to your app, there is a chance you can get the money back by contacting the bank or financial institute.