As I said, it means that you have some errors in your procedure CALL_WEEKLY, so that procedure does not run successfully. When this happens, Oracle does not compute NEXT_DATE parameter from your INTERVAL setting. Instead it reschedule the job with a short delay. If also the second time the procedure runs unsuccessfully the job is reschedule with a longer delay. This repeats up to 16 times, allways with doubled delayed time. After 16th failure the job is marked as BROKEN.
Only when a job is run successfully the setting of NEXT_DATE is set according to your interval parameter.
In your case you must find why your procedure runs unsuccessfuly, correct the error and reschedule the job. To find out what is the problem with your procedure, run it manually. In the meantime you better remove that crippled job from your job queue with DBMS_JOB.REMOVE procedure (and don't forget to commit!).