I had the same thing happen to me in Surco in 2018.
I had a native Peruvian go with me & we threatened to fill out a complaint with the Libro de Reclamiciones book (hope this is the exact name).
Legitimate businesses hate replying to the Libro complaints.
It should not be but take a Peruvian citizen with you; they will change their "tune" quickly.
Best wishes & stay safe.