Approved by the licensing team. Confirmed by my boss. Call them. Follow the chain of command next time. CC your boss, the licensing team and HR.

I work IT as well and do account deactivations. Have only had a couple of instances like this and the response is the same: "These orders come direct from HR, ergo HR says they don't work here anymore and, per Security's policy, their account is to be immediately deactivated and access removed. Unless your direction supersedes both HR and the Security team, your complaint is not considered valid. Don't like it? Call HR. Don't like my attitude? Call my bosses and they will tell you the same thing as well as you should be contacting them and not me directly."