HSN Networks Perungaluthur Chennai - Fake product installed and services not completed in full

Purchased CP Plus IP *MP Day and Night Camera(** Nos) with in-built MIC facility, Hi-Focus Video Door Access Phone(* No) with * Indoor and * Outdoor Unit from HSN Networks, Perungalathur for Rs. **,*** altogether on Dec *, ****(Invoice Date). We were told * Year Warranty for Camera and NVR. However * camera is totally not working now. Moreover all camera do not have in-built MIC either. We are cheated. Followed up, called up, messaged up, whatsapped many times. No response back. They have not attended to us till date. On engaging another local technician, we came to know product installed itself is Duplicate CP Plus product and cannot be covered under warranty. This is a big loss for us. They are not coming to service/replace product with genuine ones. We end up engaging different technician, pay additional money to set it right.
We have paid almost Rs. ***** in full out of Rs. ******(left for installing in-built MIC) which is also not done till date). We had paid Rs. **** also while we were attending brother-in-law cremation.Please help in recovering loss of money.