As of today, there are no special credit card numbers to simulate those problems. However, due to demands from the community, this is currently in the backlog for being implemented. I'd suggest to send an email to the support, to show interest on this feature. The more requests, the faster the feature will be implemented.
EDIT: PAYMILL now offers a special MasterCard number, which will fail if a certain combination of expiration month and year is used. For instance, the card 5105105105105100 will fail due to RESPONSE_BACKEND_BLACKLISTED if the expiration date is sent as 02/2020.