consumer rights?

What type of attorney would I need if the Clinic is overcharging me and sending these charges to a collection agency even though I have spoken with the clinic and the collection co. and showed the paperwork proving the charges were payed 2 years ago. Neither will work with me nor give me all statements. They say its our problem we should have kept record of this ourselves. Then I recieved a letter from the collection agencys attorney about this amount and replied in writing that this was being disputed with the clinic and how I was refused these statements. Now the attorney has sent this in for judgement.