Dear Rutmer Faber, We sincerely apologize for the setbacks and delays caused during our cooperation. Your feedback is invaluable, and we take full responsibility for communication errors and unexpected price adjustments. Initially, our quotation was based on preliminary requirements, and we made an incorrect estimate of the cost as we did not receive specific samples. However, during the sampling development process, the complexity of workmanship and the high quality of materials led to significant budget revisions. Sorry for not updating you in a timely manner, and thank you for taking the time. To prevent recurrence, we have implemented: Enhanced cost assessment protocol for accurate initial quotation; Transparent progress updates for each milestone; Dedicated to project supervision to address risks early on. We value your trust and are willing to discuss compensation or discount rates for future projects to rebuild our partnership.