My Mydin can reload with CC with charge RM0.50 per load of any amount from opening to closing if all system OK....

Make sure they reload 1 time if not they ll charge another RM0.50....

the charge is 50 cents/transaction

no such thing, unless they ran out of top up quota
if they tell u to reload RM150 twice to get RM300, report them

Hi hye, good info there. I always get puzzled, annoyed and helpless by such merchants and resort to cash term. 
As I reckon lyn forum is a good channel to educate fellow Malaysian on our rights (and many other things), I was thinking what to do next.

So, to report them, which channel is more effective? Visa/Master or issuing bank? Is there a specific email id to use? (keyword: effective. We don't want our complaints just turn into trash.)
Then, what details to provide in our report? Since the merchant put total sum (product price + surcharge) on the receipt, I guess we need to snap a picture of the product with price tag, then write the story and indicate the merchant name, address, and send the receipt as proof.
Or unless, you are saying we can also report them without actual document proof, i.e. been told there is a surcharge but we paid with cash.
(The keyword here again is effective report.)

I know this abnormal "norm" is hard to be changed overnight, but I urge all of us to do our part with hope for a better tomorrow. 
What are your thoughts, guys?
If anyone had experience on such report and/or received reply from visa/master/bank, do share the details here.