A man who has many things to do, should not hesitatu to deal with even an ungrateful person. If successful, one can enjoy happiness. If unsuccessful, one loses respect.
अर्थी तु शक्यते भोक्तुं कृतकार्योऽवमन्यते। तस्मात् सर्वाणि कार्याणि सावशेषाणि कारयेत्॥