Client analyzer to find those who paid SE tax:  Available

Client analyzer to find those who paid SE tax on a balance-due return:  Possible

Client analyzer to find those who told you they wanted to defer SE tax but have such short memories they need a phone call to explain it once again:  Priceless

Cost of a second  line so people can reach you while you are reaching out to others who may have better things to do before a Labor Day weekend:  Check with your local phone company.