Just to be sure everyone is aware, this is a pear-to-pear forum, users attempting to help others with issues involving spam and/or SpamCop in particular. I do not have any direct connection nor official position with SpamCop. I am not a lawyer nor do I play one on TV. With all those disclaimers:
I would suggest you scrub you emailing list to removed those "users" that do not want to receive your emails. Of course, assuming you do have a current business relationship with the addressees of you emails, your emails are not technically spam, unsolicited commercial email. However, it is obvious some recipients do not want to receive your email. Just as a matter of good business it should be remembered that the email standards do not guarantee the timely delivery of email and therefore any important business correspondence should not be sent only by email.
It is apparent that there are several addressees that have reported the email they received. It requires several reports, in a short period of time, to add an IP address to the SC blocklist. You can check if your IP is listed here. There is also a possibility that an email from your system was addressed to a spam trap.
This is just me, but if I received an email stating " funds due and the amount that they will have to wire to our bank by the date stated" I would be tempted to report it as spam just like all the other similar emails I receive on a daily bases, unless I recognized the sender and had opted-in to receiving email from them.
Anticipating a suggestion, it would not be appropriate to "white-list" your IP address. The correct action would be not to send email to those that do not want to receive them.
Without any knowledge of you, your business or your relationship with those that have reported your emails, I would not want to be miss understood but it should be keep in mind, Spammer rule #1, in particular Russel's Admonition and Sharp's Corollary.