How to rejuvenate a complacent team ?

One way to get desired productivity from the team members is by setting a SMART(specific, measurable, achievable, realistic, timebound) goal. Let them compete with their own output. Raise the bar in periodic basis.

If the expectation out of the employee is communicated to him/her clearly and when he/she knows that he/she will get evaluated against those goals then certainly the team member will try to achieve those goals according to their best potential. It is also equally important to review the goals periodically with the team member and give them both positive feedbacks so that they can continue building the qualities and corrective feedbacks so that they can try to improve on them and thus motivate them to get higher productivity.

A dispute is a state of disagreement.A dispute is generally seen to be a counter productive  effort but if used in a creative way ,it can be a great tool to enhance a healthy competition.A small such dispute tool could be a weekly productivity differentiator where you rate the team members weekly based on their output for the particular week relative to their peers and also show the relative contribution of that member in the team effort.First part will lead to competition while second will boost orientation to a common goal.