Are you sure it is asking for an American PIN. Based on what you are describing it maybe that you are behind your payments and koodo temporarily suspended your account. Hence the message from koodo. Sounds like they still let you get inbound calls though. Are you on a spending limit by any chance?
Your calls are being redirected to koodo's account management team due to billing issues. The pin it asks for is the 4-6 digit pin that you setup when you activated your account. You will need to either pay the outstanding balance or make payment arrangements to be able to place calls again.