An apology needs repentance first:
The turning over of a new leaf or otherwise said as a deep regret for what one has done in the past and a sad heart that will fix wrongs done.

The obvious change of character will be a result of repentance and apologies.

If the person continues to do wrong then there is clear, obvious evidence that there was no real regret, a lie was used to get back into your good books so that you can be taken advantage of all over again.