Points not subtracting when redeemed

[Wildata]

Hi Folks, I am having a strange problem, all is fine up to the point the customer

uses his points, then the points "used"do not subtract, and are available for the next purchase,

any ideas where (in what file) my error /problem is ?

 

Thanks in advance

 

Ciaran.

 

Ps Sorry if I put this in the wrong area earlier.