Can previous landlord send "charges" to collection without noticing me about charges in the first place?

Question Details: I live in Florida. I moved out of my apartment in March of 2009, I expected a letter of my deposit on whether it will be returned or not. I never received any sort of letter. I called the complex after a month and asked about the letter. The manager told me over the phone about charges I owe from carpet damage. I never received a certified letter about this. Today, I received a letter from a collection agency about the charges I owe. Is this legal to do without first noticing me about the charges first in a letter? Important Notice