Being that it's a run that is supposed to be buried, it's likely that it needs to be replaced rather than spliced, at least for the section that's buried.
The reps are on M-F from approximately 9AM to 5PM EST. They would be the ones to tell you what needs to be done. There is occasionally a rep on during the weekends, but chances are you won't hear anything until at least Monday.
Thank you for posting and welcome to the community. I am sorry to hear the wire was damaged. The wire is supposed to be buried during installation so I would like to send a technician out free of charge to replace and bury the new wire. Scheduling an appointment for a specific day may be difficult depending on the availability of the technician. Please provide me with days and times that would work best. I will review the schedule based on your answers and present you with the ones that match closest. Also, please private message me with a primary email and the name and phone number of the person most likely to be there for the repair. This person does not have to be yourself but they must be over 18 years old. Since you may or may not have unplugged the modem in time, I will make sure the technician arrives with a replacement modem just in case.
We're closing this thread since we never got a reply from you. If you would still like a technician to come out, please refer to my previous post and send me a private message with this information.