Green Tree Servicing LLC falsely showed us in default Rapid CIty South Dakota

Our 25-year mortgage was sold to Green Tree in May. We have never missed a payment. First they never notified us (nor did Bank of America) that they were the new mortgagae holder, so we threw away their envelopes thinking it was junk. (We had paid B of A as always.) They began to call us harassing phone calls. We thought this was straightened out, but then it began again in August. We paid a month in advance (we pay by check) because we were going to be out of the country. They somehow couldn't find this payment so continued to harass us. Then they held the Sept. check and sent us letters saying we owed for two months and were in default. They notified the housing authority, who offered us advice on how to keep our house. Again, we have never missed a payment. One person said she "found" the payment but that it wasn't showing up in the right category?! The calls continue. We are afraid, now that we owe only for two more months and then we'll be free, that they somehow won't find ouf payments and will try to say we are in default. 

After reading all these other complaints, we feel we must tell our attorney about this to ensure our rights and be free of this devilish company forever. I really feel sorry for those who have a longer row to h*e.