Property Manager sent a bill for 7K + for smoke damage in unit

[Penny T.]

We've rented from the same property management company since 2006, and were in our last unit for 7 years.  Smoking was not prohibited, in fact when we specifically asked if there were smoking/non-smoking units, we were told they had no non-smoking units.  We had no problems with the management until the most recent property manager took over.  Happy to give more background, but suffice it to say we got off to a bad start and it's been downhill ever since.   I firmly believe that this manager has a personal grudge against us as a result, and we were given a 5 day notice to vacate for violating the "noxious odor" section of the lease.  We moved, and just received (at day 31 after move out) a certified letter stating that we had $7100 worth of smoke damage in the apartment "pending additional charges to be determined".   

Happy to give more details of all the issues we put up with while living here just to avoid having to deal with the manager, but really wants some perspective from the landlords and experts here.  This amount seems completely ridiculous for the unit in question.  What options do I have to fight this?  I'm in Louisiana.