Sorry, Principal. My residual and renewal commissions aren't "earned"

(CAPS are added by me for emphasis:) I am a self-employed insurance broker working only on commissions. I was disabled due to surgeries and received some income replacement benefits from 2 disability companies, one of which was Principal based on the monthly income expense reports I sent to them. Then, after receiving a copy of my tax returns, they rescinded the benefit and are now requested I repay them. They said they consider the residual income I receive each year as earned income, which changes the amount of my loss of income. Even though I had a loss of earned income, my residual income didn’t decrease since it’s based on the work I did in previous years. I receive that residual income whether I’m healthy or not, and even whether I’m working or not, and is not based on any additional work that I would or wouldn’t do over the years. Principal stated “renewal commissions are pad based on the expectation that you would assist clients if they had questions or needed to make changes. Therefore, we include renewal commissions as income earned during disability.” The contract states: “Current Earnings: means Your Earnings for each month while you are Disabled.” Earning means: “Your share of the gross revenue or income earned by all such business entities including income earned by you.” The contract also states: “Earnings do not include ANY FORM OF UNEARNED INCOME SUCH AS as dividends, rents, interest, capital gains, income received from ANY FORM of deferred compensation, retirement, pension plan, income from royalties, or disability benefits.” I believe that the residual or renewal commissions are not “EARNED” income in the years following the original purchase/sale of the insurance policy. Renewal/residual income appearing as earned income or taxable income on a tax return seems to me to be no indication of it legitimately being viewed by a prudent person as EARNED income. After all, other excluded income as mentioned above (such as unearned income such as dividends, rents, etc) are typically included as taxable income on a tax return, but are excluded from Principal Insurance Company’s formal definition of earned income. And, the list they provided of unearned income is clearly not meant to be an exhaustive and exclusive list of all types of earnings since they use the “such as” language.