national enterprize called!!!im just plain mad

how long does it take for them to get my certified letter return receipt.i talked to them today i sent the letter yesterday,today they called me twice i spoke to them the 2nd time i tape recored our conversation.the women i spoke to said they wanna try to settle this out of court,i said i need it validated before i can pay. proff of what the charges are for and all that.she stared screaming at me saying are u refusing to pay,i said no thats not it i need proff that i owe what you say i owe.and she yelled she said it sounds like a refusal to pay.then i yelled at her i said no no no you listen to me i dont know what these charges are for and how they came about i need validation you will see when you get the letter.she said we did validate it,i said your acting like you dont know what i am talking about.she said ok we will update your credit report and hung up!what the hell is she talking about there.