I bought a brand new phone Model KX-TGD210, battery fully charge, can not make call in and out

check that you got the right make of battery for the charger
some phones use a nicad battery and others use a lit ion battery
2 different recharegable batteries -- 2 different chargers required

Take back for one that works properly.

I had the same problem but different panasonic phone 1311 model, I tried the first anonymous suggestion, drained the batteries(takes 2 AAAs) and now it seems to be charging normally.. already at 3rd bar now after a couple of hours of charging. Thank you anonymous.

The set could have been on shelf for a long period and so it is possible that the battery has developed back emf which makes it difficult to charge to the full level.
Also sometimes the set fails to lock on due to the same reason and also if the threshold of voltage does not come up.
Discharge the battery after it has charged a bit and charge again.Allow the battery to be put for charging for over 24 hours. If there is no registering then you must try and see if the warranty on the new phone is applicable as the base and handset could be out of sync..

DEAR FRIEND, TRY AND GET AN ORIGINAL BATTERY FOR YOUR PHONE.

go to call setting to unbarred outgoing calls and the incoming calls.

download manual
you phone must in the menu paggin the base unit if this are done the phone are connected and you can ring out or anser phone

A friend that worked for GTE advised me some yrs ago to do this and I have NOT had a problem with another battery since
when you get any new Battery charge it plugged in to the ac AND phone jack for a minimum of 24 hrs without using it.
all batteries have some memory and deminish power over time but if it was NOT fully charged to begin with as a yr goes by so does the battery life. hope this works,

Too costly to fix. bought a new phone

replace the mobile phone charer and then try