Customer Credit Limit gets changed automatically

We have customer with profiles associted with them. e.g. one of the profile is "100K" which means the customers with this profile have 100K credit limit. Based on order volume, for some of the customers, we increase the credit limit by overwriting the profile amount - to say 200K. rest of the profile attributes remains same. During customer updation some event is triggering profile re-application, as a result the profile swtiches back to 100K. We are not able to identify the event which is flipping the credit limit ie re-applying the profile for that customer.

Could you point us on how to identofy this event which is triggering the profile credit limit flip in the system. all pointers appreciated.