Not true.
Here are the rules for charge;
You must have a clear path toward the opponent, and nothing can hinder your movement (such as difficult terrain or obstacles). You must move to the closest space from which you can attack the opponent. If this space is occupied or otherwise blocked, you can't charge. If any line from your starting space to the ending space passes through a square that blocks movement, slows movement, or contains a creature (even an ally), you can't charge. Helpless creatures don't stop a charge.
If you don't have line of sight to the opponent at the start of your turn, you can't charge that opponent.
Here are the rules for ready:
You can ready a standard action, a move action, a swift action, or a free action. To do so, specify the action you will take and the conditions under which you will take it. Then, anytime before your next action, you may take the readied action in response to that condition. The action occurs just before the action that triggers it. If the triggered action is part of another character's activities, you interrupt the other character. Assuming he is still capable of doing so, he continues his actions once you complete your readied action. Your initiative result changes. For the rest of the encounter, your initiative result is the count on which you took the readied action, and you act immediately ahead of the character whose action triggered your readied action.
So here is the chronology.
1. Player A: Readies an action to move away before being attacked on a charge.
2. Player B: Charges player A. Player B MUST charge to the closest square. Which is determined at the moment of the charge.
3. Player B charges to the square, and having finished the "move to the closest square" starts to attack.
4. Player A intterupts Player b's turn - and either moves away (but he could just as well attacked and 5 ft stepped).
5. Player B's turn resumes with the ATTACK. He may attack anyone he is adjacent to. However, he may not move again, take a different action etc.
Why this makes sense:
a). Player A risks his turn. If player B had made a simple move and attack player a's action would not trigger.
b). Player B chose a tactically risky move. Per the d20 srd, movement rules while charging are tightly constrained. Player B enjoys certain benefits - he may moved up to twice his movement, he gets a bonus to his attack, and he may use feats that trigger on a charge. He must therefore ALSO accept the limitations of that move. (Ie., he must move in a straight line, etc.)
c). This example conforms exactly to any number of other actions
Suppose Player A was to ready shutting a door in the face of B who was going to charge?
Suppose player A was readying shutting a door to block line of effect from a spell?
All of these readied actions are valid, consistent and correct with how a readied action can be used to block or end the action of Player B.
In fact the rules specifically say..
"Assuming he is still capable of doing so, he continues his actions once you complete your readied action."
The rules include the words "assuming he is still capable of doing so" because Player A's actions may thwart or foil player B's. (For example, shutting the door, blocking line of effect for a spell caster).
Learning how and when to ready actions is a huge part of stepping up your game.