AMO sends me to court.

Hi, i had a debt on a car loan which i didn't pay, the bank sent me to collections and AMO was on the case. I never received any letters from them, but i did get some calls, early in the morning which i ignored.When i checked my voice mail all i would get was this message "This is AMO recoveries with a message for (My name) If you are (My name) please press 1..." Well we all know what happens when you press 1 on a voice mail call. I tried calling the 1800 number which showed on my ID, but to my luck all i got was"Thank you for calling AMO recoveries, if you know the person you are trying to reach dial the extension, otherwise enter your reference number". I googled AMO recoveries but all i got was their Georgia office, and couldnt get to a person because i had no information on the account. I took me about a week of researching and i found a number for their Portand office, i called i few times but no one answered. After a week of trying to get a hold of them miraculously someone answered. I gave the my name and they pulled my name, i made arrangements to make monthly payments and paid the first installation. The representative told me that i would be getting some mail soon. I asked about the phone issues, and she told me they were switching offices and having some issues with their phones. After that point i never heard from them again. Until yesterday, some lady knocked on my door asked if i was (my name) when i said yes she game me a court slip. The slip said that AMO had been trying to collect a debt and i had not replied. I knew i had to pay but i never got any mail from them, their new number or any reference number. I'm not sure what im supposed to do know, any help would be greatly appreciated.