One lesson I learned a while back is that Glass and Graphite don’t mix. They bend differently. In short both being tubular - when bent form an oval. One material forms a smaller oval then the other causing one tube to crush the other. Then you’re back to repairing again.
The most difficult task you face is in locating a piece of graphite that can match both top and bottom. Ask you’re friends - if they are like mine they have a few broken rods laying around.
Try contacting the manufacturer - sometimes they can be helpful as well.
You don’t mention if you built the rod or bought it finished.
If you bought the blank and built the rod, call the blank maker - perhaps they have sections that you can purchase. Then cut off the components, rewrap the rod and finish it.
I broke the rod I built on a Dan Craft Blank --very badlly with 2 broken sections. I called him, sent the broken rod to him, he matched the sections and returned it all to me and I now have the rod working again.
If the rod you broke is a production model try panfishers suggestions.
Ortho, I did build the rod and oddly, it is a Dan Craft Blank BUT it was a disco item, marked as no return…so no go.
I won’t at all contact him for this issue…my experiance with him and his company was GREAT so no way I’ll try to get a bit more…though sure he would try.
Spoke to him on an unrelated issue and no way, no how this gets sent back…again, this is no biggie…just a thought for a winter project.