The TOM-TOM GO720 starts up automatic and unintended after about five days when it is switched off. If it is not plugged in than it will complete discharge its battery. After some time the battery is gone. TOM-TOM completely ignores calls on this software bug. They never repaired it as far as I know. Indeed is the question how to repair or replace?
Do what I did and complainin a civil manner and I got a repair FOC and they sent me back a replacement unit (new) followed this up with a complete accessory kit as they did not return the items I sent it back with.