What is the ruling on donating the value of an item that was mistakenly not included in the invoice, with the intention of conveying its reward to the store owner?

If it is impossible to deliver rights to their owners, it is permissible to give charity on their behalf. However, if it is possible to deliver them, giving charity is not sufficient unless they agree to it. Based on this, giving as charity what was mistakenly taken from the store is not sufficient; rather, it must be returned to its owners by any possible means.