microwave bought

Ms Vorsatz bought a microwave oven from the above mentioned store. She had it returned twice already and then it works for a short time them conks in again. This morning when she switched it on it blew the mains in the main house (she lives in a flatlet with her own little distribution board) and she is 89 years old and truly nearly had a heart attack. She is moving into an old age home before the end of the month and MUST have the microwave. I phoned the store on her behalf and Donovan kindly assisted me by advising he will get back to me. All I want is someone to act immediately as she MUST have another microwave now. Please see to this immediately and sort this out before the close of business today. She is in a state as she cannot afford to just go to a shop and buy another oven. I await your immediate response.