HER2 Breast Cancer Level 3 Not Responding To Chemo After

HER2 breast cancer level 3 not responding to chemo after 2rounds. Due to have breast removed in January. Now they want to go me herseptin and different chemo. Am I not wasting time and risking spread to lymphatic s. Shouldn't I insist breast removed now or at least another scan after first round of new treatment. Very worried.