Product: Mortgage

I have had a second mortgage with XXXX XXXX XXXX for more than 3 years that went well. Last XXXX XXXX XXXX XXXX XXXX sold/ assigned? my loan to Dovenmuehle Mortgage , Inc . 
With XXXX XXXX XXXX I had an automatic payment set BY THE BANK to withdraw the minimum monthly payment. On top of that I made extra payments online through their website. Both my checking account and my home equity were held by XXXX XXXX XXXX. 
I had no idea about the above transaction until in XXXX of this year XXXX ( five months later ) when I received a foreclosure notice from Dovenmuehle Mortgage , Inc . It was at a great surprise as I have never heard of them. They said that they had bought the loan and I was in default. I tried to work with them to set up an account immediately and pay online. I was " blocked '' to pay online as I was " late ''. They allowed me with a fee to pay by phone to date. 
After that I started to look into the account because I knew I had made payments online at the XXXX XXXX XXXX website every month to go towards principle for all these years and most of the time my extra payments were more than a regular monthly payment. 
Then I realized that some of the payments were just deleted. For some of them the money cleared out of my checking account bank but they were never posted to my mortgage account. 
Every month I continue to make payment to both the same way, I paid online at the XXXX XXXX XXXX  and I paid to Dovenmuehle Mortgage, Inc as I did not want to lose my house. Surprisingly this was repeateing over and over. Some payment are posted, some are not. Every month, when I get a statement, I called XXXX XXXX XXXX and they confirmed that the money has been cleared by the bank and that Dovenmuehle Mortgage , Inc should have posted and then I called Dovenmuehle Mortgage, Inc and they sayd they will look into it. Couple of times I was on conference call with both XXXX XXXX XXXX and Dovenmuehle Mortgage , Inc . The representative named XXXX of the XXXX XXXX XXXX at the extension XXXX was the first nice to go through the statements to confirm my complaint that money has been out of my checking account and never had been posted towards my mortgage. I paid {$20000.00} a month ago to try to close this account and get rid of them, however I do want my money paid to show on the account and have a fair balance. My XXXX XXXX XXXX  statement shows now {$7400.00} while Dovenmuehle Mortgage XXXX Inc shows {$8500.00}. It is more than {$1000.00} difference because of the multiple payments that shows on XXXX XXXX XXXX home equity account, but never showed on Dovenmuehle Mortgage, Inc account. They promised me a month ago that they will revise all payments made towards XXXX XXXX XXXX. This month, when I received another statement without any modification I called the bank to tried to reach XXXX. He was unreachable for a whole week. So I decided to contact you to help me. I have printed out everything starting XXXX XXXX with payments made, deleted, cleared money out that were never posted. 
On top of that in XXXX they reported me a month late, even of I made multiple payments every month for years including that month but they were never posted. 
Where is my money? 
I am attaching my most recent information and I know that they both show XXXX XXXX XXXX. However the one with XXXX XXXX address is actually Dovenmuehle Mortgage , Inc. You see, there is no Dovenmuehle Mortgage, XXXXc anywhere, however they hold the account.