1. How did you upgrade the card ? Did you fill up a form ? (This is to determine B&W proof of your application and card of choice) I hope there's physical evidence of the upgrade and the card of choice.
2. It's clearly 2 different product at the physical level. Physical product and system information must match. No point allowing the ambiguity because merchant will only trust what they see.

You need to visit item No.1 because you may encounter problems if you want to cancel and reapply quickly. If the Amanah card does not meet your expectations, cancel the card immediately - tell the bank nicely and firm that this is not something you want to use due to the limitations of the card. Plus no point paying the RM50 fee for something you don't like.

No problems.
For such cases, it depends on the situation. Normally if there is a declination of the transaction, it may be your fault, the bank or merchant's fault.

1. Your fault - if you missed payment/exceed CL, etc and the bank temporarily blocks your card.
2. Bank's fault - problems at the bank's gateway
3. Merchant's fault - bad connection at the terminal, merchant's bank problems, etc.

One thing I would advise to do is don't bother to ask your bank for help. In my many years of using cc, 80% of the time problems originates with the merchant itself. Quick check to the bank and the bank says they could not see any transaction going through. It doesn't help that the merchant is quick to blame your bank and not theirs. Believe me, this behavior/reaction is consistant all over the world. For some unexplained reason, some banks are worse off than another especially when you are overseas - eg. Bank A merchant terminal in Thailand would not be friendly to your cc unlike Bank B merchant terminal.

Situation is better in Malaysia but it may happen sometimes.

Best practice is to have another card from another bank. It is unlikely that 2 bank's gateways are faulty at the same time.