why use refunders for everything..

As mentioned above, some people just don't feel comfortable doing it themselves.

It may be easy, but it's also easy to pay 8-10% of the items value then just sit back with no hassle and receive the refund.

Maybe if people charged 20% plus for a refund I'd agree with you, but 10% seems fair to me.

how to get refund a mobile phone total price by Amazon??

Just dont turn the phone on I guess when you receive it from the carrier until the whole process of the refund is done.