Hi,
As Abbie said in an earlier post, you should ask about this in the Writing Forum.
I have a couple of brief comments. First, motivate a claims payment does not seem like a clear phrase to me. Do you mean you want to make a claim?
Second, what is the claim for? Did an elephant sit on the client's present? Was it hit by lightning? In other words, you are not giving us much information about the nature of the problem.
Best wishes, Clive