Understand the refund policy
Check whether there is a refund policy when purchasing for the first time and understand the refund period. If you are still in the refund period, you can try to contact the manufacturer or after-sales service provider to ask about the possibility of refund.
Looking for technical support
Try to find official website or other official channels for advanced learning machines and seek their technical support. They may be able to help you solve the problem that you can't download synchronized content, or provide an alternative.
Seeking protection of consumer rights and interests
If you buy the service or product of advanced learning machine, but you can't get normal service, or you encounter the problem of consumer rights protection, you can seek help from relevant local consumer rights protection organizations or departments to understand your rights and ways to protect them.
take action
I suggest you act as soon as possible, communicate with relevant parties and learn about the possibility of refund, technical support or rights protection. At the same time, in future purchases, we should pay attention to choosing reliable sales channels and products, and fully investigate and understand relevant information before buying to reduce the risk of being cheated.