On what date did the customer with the lowest credit limit serviced by sales representative Barry Jones make payments for his/her orders?
SELECT T3.paymentDate FROM employees AS T1 INNER JOIN customers AS T2 ON T1.employeeNumber = T2.salesRepEmployeeNumber INNER JOIN payments AS T3 ON T2.customerNumber = T3.customerNumber WHERE T1.firstName = 'Barry' AND T1.lastName = 'Jones' AND T1.jobTitle = 'Sales Rep' ORDER BY T2.creditLimit ASC LIMIT 1