Need GST help for my business

Aman Agrawal (Student) (36 Points)

22 June 2021  

I have a manufacturing unit of Plastic Pipes.. I purchase old scrap pipes from Farmers directly and reprocess it and than sell it to the farmers directly. 

Problem is.. scrap pipes rate is 5% 

New Pipe rate is 18% 

Farmers are unregistered person.. how can I deal with it .. how should i raise invoice.. can anyone help me