If you can find a url that has that number in it, sometimes you can see what site it is by looking at the url. google is quite helpful with that at times.
Or, you can write to
support@ccbill.com with a subject of:
AFFILIATE ACCOUNT QUESTION
and say: Can you merge 123456 with my existing account 234567 and tell me what sponsor 123456 is?
Generally, 4-6 hours and you have your answer.