trying some cc terminal

Ipay sunmi device, Coherent+, Fasspay is not suitable

reason :
user can switch off the device.
Fasspay (by Softspace+HLB) won't allow re-query of transaction to check transaction status, which is kinda silly
Conherent+ has no programatic api to check for transaction status

what I need is :

1) a credit card/pay wave terminal where my program can re-query transaction status via web api
2) a terminal where the user cannot access on/off button
3) the communication can be either COM or WebSocket or via web api calls

any recommendations ?

supposedly if during any of the process the device is turned off, the transaction should be cancelled. Basically until the receipt starts to print out, the transaction shouldn't happen.
Once the credentials are confirmed, the transaction should be queued, then once the terminal has informed the user it should then inform you that the user is informed, so you can then forward the transaction.

All those you mentioned are payment gateways that deal with the banks for you. Consider web based bank transfer or a different gateway. I use toyyibpay and in the past their API was absolute crap but they've refined it today.

I need cc terminal device for kiosk applications for user to use credit card to pay for stuffs

just use the cc terminal everyone use nowadays, that itself is an android device. May suit what you're looking for.

Last time I used SUNMI P1, websocket programming.