Upset for the sake of RM5 late charge?

Oooh..., in this lovely and sunny Sunday morning, it should make me great and spirit-uplifted.
Then, once I have checked the banking online credit card bill, ophhsssss, I spotted a Wondering 'late payment charges-RM5' in my last month statement.

A thousand Q in my mind even if i got pay it on the exact due date time.
Is the bank mistakenly charged and printed?
Is the bank hanky-panky treat with this 'hidden cost' stuff?

I got a bit mischievous and irritating, and make a call to this 'oversea bank' about the matter. What the operator reply make me more unbelievable and annoying, which is due to the 'Cheque' is needed for clearing for 2-3 days in central bank and then only the bank only 'recognize' the cheque once is cleared for this process.
Can I loose my temper and throw a tantrum like a toddler to this innocent operator, even if she agreed to waive it for this time but advised me to pay in early day than the due date?

Ya, a good reason and explanation we should really appreciate.
But, don't the bank understand the consumer's knowledge about those 'banking system process' is ZERO?
As a consumer do we have to know about the bank to process the cheque payment in 3-5 days early than the credit card due date?
OMG, then as this marvelous and well-known oversea bank SYSTEM should be enhanced to be more SMART enough to cater this rather than 'I' act as a 'fussy' bank customer, that really jeopardize my high-spirit passion for the sake of the RM5 late payment charges, to make this ridiculous COMPLAIN in this wonderful Sunday....

Just loose the temper away and let go. Cool down.