What do I need to ask customer service to buy a mobile phone online?

Hello, you need to consult customer service online for returning mobile phones. Do you support returning goods if there are quality problems? Secondly, do you support returning goods for no reason? In addition, find out whether there are gifts, gifts, accessories, warranty issues, after-sales treatment issues, other configurations, advantages and disadvantages of mobile phones. Just ask everyone whether it is good or not, and the seller will naturally say everything is good. Anyway, think about what you need. I hope it helps you. Thank you.