Owners Equity not funded

Company has 3 owners. Owners A and B each have a 45% stake, Owner C has a 10% stake.
Owner C did not fund their 10% at the onset, $100,000.00.

--Owner C owes $100,000.00

--Per their agreement Owner C is due to be credited $30,000.00 towards his Equity for commission based services performed for the company for which he was not paid. In addition, they have recently made a $5,000.00 payment

--How should I record the amount that they owe to us? as a Loan/Due From/Spreadsheet?

--If using a liability to record what is owed how do I record the most recent payment to record it towards the liability and the Equity.

Thanks in advance.