Accident Victim being harrassed

I was involved in a motor vehicle accident whereby I was in an out of hospital, put off from work. I am insured with Hollard insurance who gave me a courtesy vehicle until I get my vehicle replace or repaired. After getting out of hospital and back to work I have been very busy and have been contacted by First Car Rental to report to the branch to sign a contract to renew the rental on the vehicle. According to the document it was supposed to be returned on the 2nd January. Then I get a call from First Car Rental to return it on 31st January which I do not understand. I have been very busy at work since getting out of hospital and could not make it to the branch yesterday 13 Jan 2016 whereby I made an arrangement to sign a contract to renew the lease of the vehicle at my own expense including the days that were overdue. Yesterday I had a late afternoon meeting and could not make it. I get a call from ROB HILL at 7PM harassing me and threatening me, to open up a ******** case against me for theft and breach of contract. Told him that I will take time off work to go to the branch as arranged to renew the lease, however he threatened me. I am not a ********! I would not recommend FCR