Jail Threat When Making Payment Arrangements

[interested party]

I recently moved from California to Massachusetts. My job in CA didn't pay enough for me to make my car payments on time. I was on the repo list, being four payments behind. I paid two payments at one time about three weeks ago. I got a new job in Massachusetts. When I called to make payment arrangements, I got harassed into setting the date for payment three weeks before i got my first paycheck. When i got the threatening calls, i informed them that I could pay at least one of the two late payments when i received my first paycheck. They became irate to the point of screaming over the phone. I hung up. I got my first paycheck yesterday and called to make a payment. They claimed they wouldn't accept it unless I paid the entire amount, which is now two months (including Sept.) I explained that I could pay at least one month every two weeks, as I got paid, perhaps more. I haven't received my first FULL paycheck yet. They have threatened to have the police come to my job in Massachusetts and take me to jail, then they hung up. i paid the one month via Western Union Quick Collect. Then, I called the car company and gave them the confirmation number. I also made arrangements via post-dated check, to pay the second late payment in two weeks. My question is, should I expect to be arrested at work today? According to the car company, they wouldn't accept my partial payment. However, it seems that they did, according to Western Union. Also, the next person that I spoke with did in fact make a payment arrangement with me. Also, is it legal to ask for a post-dated check for a car payment?

[Mr. Knowitall]

Is this a collection agency doing the calling, or the original creditor?