Mvat excess payment paid in q4

One of our clients has made an excess payment of MVAT in Q4 FY 2013-14 of Rs. 14,00,000. We realised that now. Can we set-off that amount against liability of Q1 FY 2014-15, if yes, how much can we set off Rs. 1 Lakh or 5 Lakh? or will we have to claim a refund in Form 501 ? Please reply as early as possible. Thank you. Saloni