NO CALL NO SHOW

hi my name is justin jose, and a week ago i left the office because of an emergency issue. The management allowed me to go on halfday provided that i can present a medical certificate. the next day I went to the doctor for check up and was advised to rest, so i called the office and told them that i cannot go to work because of what my doctor has advised. Today the problem is they are asking me to sign an "corrective action plan" for being NCNS (no call, no show) eventhough i've already submitted my medical certificate and called in to let them know that i cannot go to work during those times.

my manager told me that the reason they gave me NCNS is because their rule was i need to be at the office and recieve ateast one call and then i will be pulled out and payed by the hour of my stay there. doesnt make any sense!
can some one help me with this issue?

just make sure you are able to explain fully the sequence of events and submit the documents that you have.