It sounds to me like the client needs a bit of coaching on being
timely and about how being timely will affect his/her life and
business. I think that people do certain things only because they
believe they will avoid pain by acting that way.
If you can be assertive with the client, simply bring it up and say
that in order for you to continue your work together, the client needs
to be timely and that failure to be timely will result in fees.
Hope I could be of help!
Anna Kubit
Konsultar Cor****ation
konsultar.com