Defected item not replaced immediately.

Misinformed by call centre and pathetic service. I am inconvenienced deeply. I purchased a ryobi brush cutter in November. Tried using it in december for the 1st time and the device cut off after a few minutes of service. This is a defected item and the store refused to replace it. Surely the device can be sent for repairs or claims thereafter but as the customer i should get a replacement immediately. The call centre assured me that the manager will be able to do that but when i went to the store they couldnt. I now have to wait 21days. Can you imagine what my lawn looks like. Im at high risk of snakes and my neighbours are asking me why im not attending to this. And bdw the repair centre only opened after the 8th of January. So its more than a month without it in service.