The life insurance rider that pays the face amount plus the total premiums paid into the policy is known as:

Death Benefit

Explanation:

Based on the information provided within the question it can be said that the life insurance rider being described is the Death Benefit. This is a rider, that like mentioned in the question pays the face amount of plus the total premiums paid into the policy. These premiums are waived if the individual insured becomes completely disabled before a pre-defined age.