i didn't played for a while but 5 of my characters got deleted somehow.

i didn't played for a while but 5 of my characters got deleted somehow. can i restore it back. i dont have enought points now and dont want to donate.

Few options:

Frostmourne player: https://www.warmane.com/account/services and transfer your characters from Frostmourne to Icecrown. They may appear in https://www.warmane.com/account/barracks once moved.
Decommissioned realms: Transfer windows are closed.
Player deleted characters: Picked clean, and deleted. Chances are it was done ages ago. Re-secure your account.
System deleted characters (inactivity cleanup): No restoration.
You logged wrong account: Log the right one.

System deleted characters are up to level 50. If deleted characters were level 51 or more, chances are they were deleted by a player.

Why are decomissioned realm transfers closed?? 1 got that for 3 times now. wotlk, Cata, Pandario...... in the dacade i played here.

All max. level characters.... please inform me private on how to deal with this.

There is no dealing with this beyond what his post says. The only transfers from a closed server currently available are for characters from Frostmourne's third season, which are done in the way his post already describes. Anything else, including the first and second seasons of that server, aren't available anymore. In all of those cases free transfers were open for at least a full year, in some cases even longer.

Is there a pssibility you get a lvl 80 voucher just like the migration from Molten Lordareon? then you only need to re gear.

No, there isn't.

I know right? They could at least announce these things in advance so we're prepared to transfer stuff... oh.. wait... they did...