Extended warranty

I just bought a HI 9 Plus tablet with 4G LTE and wifi to be used as my phablet. I also paid for 3 years of extended warranty ($84.99). I only received a standard (one year) warranty card. How do I activate my extended warranty and where to ask/receive service when I need it.
谢谢你。 Thank you.

Please write to aftersale@chuw.com.