Call the court clerk back again or go to the court clerk's office and find out how you can file a motion for a continuation date or to remove a capias, or otherwise to deal with this before they decide to come looking for you.
You have raised some potential defenses, but that does not do you any good unless you can go. There is a book called how to beat your traffic citation. Once you get your case restored I highly suggest that you either retain an attorney or read this book.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.
Calling on the phone is usaully a waste of time as you see. Click on the FDHSMV below, put in your Driver's License and see if it's suspended. If it is, do NOT drive. I would not wait for a court date. I would go to the court, sit in the courtroom where a judge is--usually first floor, sometimes second floor. Sit near the front, near the judge, wait till everyone else goes. They will ask if anyone else is left. Stand up, tell them you forgot your court date in January, you are here now. Show your driver's license, and your proof of insurance, and the registration of your bro-in-law's car. You should have a DL and inurance if you are driving, but you are not required to register your bro-in-law's car. So you need proof that it is his car and not yours. The judge might turn you away and tell you to get a new court date. If so, go over and see if you can resolve things with the clerk. If you get there and there are no judges presiding, see if you can work things out with the clerk. I would just go the the main Criminal Justice Building on 1351 NW 12th Street. You don't need appointments to see clerk, but if you license is suspended--I doubt it--you usually need appointment to see the DMV (FDHSMV). Please click on my website, it does not cost anything. Thank you.