What are some way I can earn back my phone?

56 days is a bit excessive, ask for it back, if they refuse throw a tantrum in front of them, throw yourself on the floor screaming, crying and shouting, how life isnt worth living and you wish you had never been born - the full works - you are still young enough to get away with it.

the next night do the same thing, they will soon give you your phone back rather than listen to you crying and whining all night

you could try spending more time unpacking

Its too late. After 56 days your parents have learned you don't really have a need for a phone so likely won't see one of your own until you are much older, or can buy one yourself. Wish you had asked this question weeks ago.

Well if there's still unpacking to be done... But 56 days after there shouldn't be. Start cooking, taking out the bins and whatnot. Otherwise just ask for it back. Say the punishment has gone on long enough for not helping to unpack. Make deal with your parents for it because an open ended punishment is ridiculous.

No time to read your long spiel. But matters of that sort are between you and your parents. So ask them.

Maybe you are always on the phone so promise them you wont be on the phone always and you will be in the real world doing some good work.

Offer to clean the windows inside and out. Offer to take care of the garden, raking leaves during the Autumn. Offer to wash the car(s) inside and out once a week for a month.

Seriously ask and about joining a local group, take up something that doesn't involve sitting in your bedroom stabbing away at your phone/tablet/pc for hours on end. Something that will get you socialising and maybe learn a new skill or two.

Why aren't you unpacked yet?

Your parents should take away your computer as well.