On a FAS8020, e0c/0c and e0d/0d ports are CNA/UTA2 (Ethernet, FC, FCoE-capable) ports. They can be configured as needed.
Based on how you are describing your missing e0c, e0d ports, it sound like you have configured them for FC mode.
You don't mention what ONTAP version or mode you are using, but generally you use the "ucadmin" command to configure the desired mode (you want to set it to "cna" mode).
You have to reboot the controller to have the changes take effect.
For ONTAP 9 (or cDOT): (just do the opposite change --> cna)
http://docs.netapp.com/ontap-9/topic/com.netapp.doc.dot-cm-sanconf/GUID-E2CD31BE-28EC-468E-AF49-83A641575799.html
For 7-Mode, man page:
https://library.netapp.com/ecmdocs/ECMP1511537/html/man1/na_ucadmin.1.html