A:Answer We're sorry to hear about the issue with your cable. To use the 3-year warranty for your Insignia™ 4' USB-A to USB-C Charge-and-Sync Cable, start by locating your purchase receipt or any proof of purchase from Best Buy. Next, contact Best Buy's customer service, either by visiting a store, calling their support line, or using their online chat service. Explain the problem with the cable, mentioning that it is still under the 3-year warranty. The support team will guide you through the process, which may include returning the defective cable and receiving a replacement or repair. For more information, you can visit the Best Buy support page.