Poor quality appliances and refusing to fix malfunction microwave used for 4 months

I have purchased a Defy microwave on 01 March 2025. On 19 July 2025, the Microwave was not heating food items when operating it. The microwave only worked for 4 months. I then took it back to Ok Furniture to report the technical issue, and I was told to leave the shop for their supplier to check. The sales lady said that when they discover ****roaches then they won't be able to fix it. It was then that I told her it was incorrect for her to stipulate such a condition, as it was explained when procuring the item and on the receipt, such conditions are not mentioned, and Ok Furniture Gezina is violating the consumer rights to come up with excuses and an inconsiderate attitude towards the customers. The microwave was evaluated on 23 July 2025 after I had taken it to the store on 19 July 2025. Can they prove that the ****roaches were from my house or the store? Before I purchased this microwave I had a microwave from another brand for 7 years in the residence, allegedly contaminated with ****roaches that Ok Furniture Gezina was using as an excuse to honor the warranty stipulated in the invoice. I am dissatisfied with the poor quality of service received. I would advise anyone to buy any appliances from Ok Furniture Gezina, and the salespeople there are unkind and lack courtesy. They do not adhere to their own terms and conditions.