Expiry drug sent - denied receipt - accepted and then denied - thereatening us with suit of 5crores

We have sent the expiry drugs to the distributor for claims. We are speaking to him for two years for our claims. Sending emails for 6 months to them as well as the manufacturer. We also provided with trasnport receipt. They are asking for the delivery challan for the proof and denied the receipt of drugs. The drugs were expired. All these issues are known only to the distributors and the marketing team of the manufacturer. Hence we have sent our doubts to both the distributor and the marketing team regarding the fate of expiry drugs: either their intention was to cheat us or the employees might have sold the drugs illegally. We also stated that we will issue complaints to other government agencies and launched a complaint with central drug control dept and marked a copy to them. The distributor accepted the receipt of the expiry drugs and said a format was missing (which they haven't provided to us till now) and said they will launch a defamation case for 10 lakhs. After that the manufacturer has stated that the distributor has not received the drugs and format and said a defamation case of 5 crores will be launched. Both the statements of distributor and manufacturer are conflicting showing intentions to cheat us. Also the fate of the expiry drug is still questionable that will affect the health of the nation. what should we do now.