Complaint Review: Harris County Toll Road Authority

I received a Toll Violation Invoice stating that I owed the HCTRA $37.50 for 3 tolls and $33.00 administrative fees.  The charges were dated 12/30/11, 12/30/11, and 08/27/11.  I admit that I was forced to go through the EZ Tag lane, because of traffic I could not get in the pay by cash lane. I had a roll of quarters to pay the tolls.  My son lives in Katy, Tx and I do use the toll road.  But, I did not on 12/30/11 at 11:40 am and 12/30/11 at 4:30 pm go through the tolls without paying.  I am a senior citizen, clean driving record, maybe 1 ticket since the age of 16 and I always buy a role of quarters before going to Katy.  I was sent a picture of my car for one of the violations, but why not for all three?  Now I have received a letter from an attorney charging me $79.50 for $4.50 of unpaid tolls.  This is so wrong!  I am a law abiding citizen and would not go through 3 tolls without paying.  I know for a fact, that I am guilty of 1 on 12/30/11 @ 11:40am.  But, why am I just being notified that I went through a toll on 8/27/11.  I was also told that if I get an EZ tag, the administrative charges would be dropped.  The $33.00 admin fee is a rip off and now $79.50, what's that for?  I could dispute it, but there is no one to dispute it too.  I'm really at a loss.