Did Citibank overstep its boundaries when i arranged a payment plan with them to get my mortgage reinstated and they referred my account to a law firm

I set up the payment plan in early August for a payment to be made at the end of August. About two weeks ago i received a notice from a law firm saying that my mortgage account from Citibank has been referred to them for possible foreclosure and that I had 30 days to respond to the notice..About a week later i received another notice from the law firm saying that i owe them $3000 (that's the amount i owe Citibank on my mortgage PLUS the outstanding amount i owe in maintenance fees to my co-op management company) . The notice said I had to pay that amount to them by the end of August. Needless to say I was very upset by this. I assumed my payment plan arrangement with Citibank would keep me out of foreclosure (as long as I made the the payment, which I had every intention of doing--they never gave me a chance!). My question is was Citibank out of line by referring my account to the law firm before I even had the chance to pay them?