Poor sirvice @ Middelburg Matrix Warehouse

I bought a power supply at Matrix Warehouse Middelburg 2 months ago. A few days ago the product stopped working so I took the defective product back(07/12/2017) because the product is under warranty, to my surprise I was questioned by the staff at the Middelburg branch on why it took me 2 months to return the product, I explained to the individual that the product is under warranty and that I have the right to return defective products to the supplier. The individual had a very bad attitude, and I feel that my rights as a consumer was violated and I was misled by the Middelburg branch, because clearly you cannot return defective/sub standard products to Matrix warehouse Middelburg even though you have a warranty without being treated as without respect.