Recovery of money

Sir , Providing the services in 2012 , then due to some financial problem the party told wait some time even though we drop the mail for invoice . In 2017, they acknowledge the bill agreed to pay the amount but again didnt mada any payments , in this situtaion can we file a summary suit on the basis of acknowledge mail of bill. And what are charges for summary suit in Noida. Pls Advice.