Credit / Debit Card Processor Charges

Please note before reading, this is not the first place I have posted this.  So this might seem like repeat information for some of you.  I'm posting this in a few different online casino forums to get a wide range of views on this topic.  So please don't be offended if you have read this before somewhere else.
So I know we have a lot of threads lately about credit cards, bank cards, prepaid cards, and the such. So what I'm wondering is. I have started noticing a trend with the newer processors that apparently, there charging anywhere from as little as $0.01 over what you authorized to skies the limits. So far the largest gap in difference between what they should have charged and they did charge was $1.07 so far. Yet if I only were to have placed oh lets say $20.00 on my card, tell them to only take the $20.00. Then the processor says there only going to take $19.97, but really take $21.07 that's ultimately going to cause a decline. Mainly because the processor is going to take way more than there entitled to.
I'm wondering if the currency conversation rate is that badly out of whack with these processors and my prepaid card that's causing this issues, or if there "skimming" a few extra cents to a buck off the top. As a profit to them on top of what there already making off the casino for processing for them.
Before we get back into people who are paying fees for international purchases or even paying by the transaction with there. I'm talking about the actual base charge. The charge that happens before all of your banks fees come into play.
So I have setup a poll, I have included a 3rd option. Mainly because I have also read about how people have become victim of rogue processors lately. So I'm also curious if anyone who just hasn't come out yet and said anything have become victim of a rogue processor. I know myself got a $0.99 charge that never did complete, but still sat pending for 2 weeks before falling off. That I never authorized.

I forgot to setup the poll, but you get the jist though.

this happens to me on my prepaid visa card everytime i deposit,  the visa card company says it is definately on the processors end (which i believe because it only happens online casinos)  it is sometimes two charges, averaging 6 dollars for every 100 or so i deposit.//////..i have contacted finance and they swear it is not them, i contacted the rep and they said they would never charge extra......and my visa company says it is the processor company.///,..........it seems like the visa company would not be able to do this.........and one more note,  the name on the charges are the same as the processors....go figure

Hmmm.  I don't think I've been victim to overcharging, in fact, it's usually undercharging by a few cents.  But there is a reason to add or subtract small amounts (not significant ones).  Or to not make your deposits always be in denominations like $25, $100, etc...

Apparently it is less noticeable or suspicious to pesky bank employees to have your purchases not all look suspiciously as if you were depositing evenly numbered amounts at perhaps some online site for which the bank is not supposed to allow.  $24.96 looks more like a more legitimate charge for goods or services  than $25 $25 $25 time after time. 

I have noticed my bank leaves some transactions as pending for a long time...days...and also then some of them disappear for a few days and then reappear, not necessarily at an opportune time.  Nothing as irritating as thinking all is taken care of and then suddenly you have the charges reappear.  I am not sure what's up with my bank, or with the charges, but I've learned my lesson a few times already.  lol.