Hi Deepthi,
If I understand your code, you are trying to change the address of the BP with address_change FM after fecthing the data from the application server. Then the status of the change you are writing as a log to the file and again kept in application server. Right?. What is the status of the job?. What is there in the log?. Did you try debugging the job with JDBG tcode?.
One more small thing, I didn't understand why you are using CRM_LOY_MEMBERSHIP_SAVE FM here. I believe the changes at membership level will automatically be visible once you change the BP.
Thanks,
Faisal