Is this a Bank of America trick?

My wife and I have four BOA credit card accounts which we have been paying online and on time. Recently our BOC monthly statements are saying we were a couple of days late on the payments even though a payment was made on or just before the due date. I talked to a BOC customer representative about this and they said since the payment online was by bank account electronic withdrawal it was the bank's fault and not their's since it took a couple of days to post a payment to them. Now I went back a few months and noted that the BOC payments previously done on or just before the due date were being posted that day and showing up on the statements as being on time.
My wife and I have had most of our work cut back so we are having to wait as long as possible on our debt payments to everyone to just get by here lately. Is this a Bank of America trick? I heard something about this tactic somewhere in that credit card companies do this to get more late payment fees. If this is the case who should I complain to? I also having the same problem with Household Bank. I don't have the problem with Chase, Discover or Sears. The day I make a payment online with them it is posted that day and not a couple of days later. If anything maybe someone can give the name and address of the BOC president so I can write to him and complain. Thanks for any help. Regards, Chris.