CDR Rating

We need someone to recommend, create and install a solution for CDR rating that will rate and create bills and invoices. Sample CDR file enclosed. We have mediated and rated cdr and Rating system needs to re calculate the charge and generate invoice according to the customer tariff plan. The rating system should be tailor made and hving capability like free minute, bundeled offer, local ,STD and ISD bifurcation as well as add on pack consideration. Asterisk knowledge is a plus, as CDR calculation of calls may be required. Previous experience designing billing systems is a plus. Please provide examples. Project will be awarded to most experienced bidder with previous examples of such work. Thank you for your bids and good luck!