The cards are listed as accepted cards in admin.
For American Express and Diners Club I receive " (TESTMODE) The merchant does not accept this type of credit card."
For JCB I receive "We only accept Visa, Mastercard, American Express, Jcb, Diners Club"
Not sure if this is anything as it shows for all transactions, card or COD.
The error log shows:
ERROR - 2016-04-20 17:51:36 --> Could not find the language line "label_order_time_type"
ERROR - 2016-04-20 17:53:04 --> Could not find the language line "label_order_time_type"
ERROR - 2016-04-20 17:54:33 --> Could not find the language line "label_order_time_type"