Design Info — Fraud and selling wrong product

I recently ordered 35mm Sony lens from design info. I was have many issues with the same lens but the product design info have sold me doesn't have MRP label And has no information of from where it is imported from. The only reason I bought the lens was that it was Sony lens but now even the Sony company says that the lens is not theirs.
When I call design info for refund they say we can't take it back.
The lens costed around INR 30k to me and the problems and troubles design info have caused me is so painful.