Two party aggrement

I have purchased some ayurvedic products from a local steet based ayurvedic shop ,since I much concisious about the issue,the ayurvedic supplier has took the advantage and started to loot me by asking some money in return some ayurvedic procts which immediately shown the effect after using it, after some days he again told we have to take this ayurvedic jadi booti then u will be normalised but it cost of rupees in lakhs. Since was becoming a case of hiplotiz ,I told him to give me that product on credit basis, then he made some conditions of payment over plan paper with rupees 1 stamp and he doesn't sign over that paper, in advance he took Rs.10000 from me . After 1 day taking the product I discussed the matter with my relative he advice me about my health problem and we decided to go for Doctor .but when we spoke with that person he has threatened us as he will create problem by showing that plan paper written conditions. Since am primary teacher am getting tence will he make some problem . Please advice me.