Product: Mortgage

I was behind on the mortgage payments back in XX/XX/XXXX, I made a repayment plan to have the account back in good standing, I was offered a repayment plan on XX/XX/XXXX to pay the amount of {$1000.00} for 12 months beginning on XX/XX/XXXX and ending on XX/XX/XXXX. I accepted the offer and immediately started to make the payments on XX/XX/XXXX as agreed. Every month on the bank website under " make a payment '' I have had the option of paying the regular mortgage payment or to pay the repayment amount, I always used the latter and paid on-time the repayment plan amount of {$1000.00}, so, everything was good. 
After making all the 12 payments which I have copies of all of them, on XX/XX/XXXX I was ready to start making my regular mortgage payments again, but to my surprise when I logged in into the bank website to make the payment, it was showing the same " our records indicate that you are currently on a repayment plan, click here to make the repayment plan amount '' I called the bank and explained that to them, they told me that everything was good, that the system will take some time to update the information, but that I have successfully paid all the 12 payments and the repayment plan was completed, that I should start paying my regular mortgage payment of {$850.00}, I did that and paid my regular payment but kept logging into the website and noticed that the account keeps showing the same info. 
XXXX arrived and I went to pay my mortgage, this time it was even worse! it was showing a month late, asking me to pay XXXX " again '' late fee charges again and everything was a mess! I called to the bank again, just to be told that in XXXX I would have to paid {$1000.00} again and that I was short paying {$850.00}, I explained the situation again and I was told that they need to " review '' the account and see what happens, in the meantime I was told to again pay my regular mortgage payment of {$850.00} once everything is fixed, it should be back to normal. 
I paid the {$850.00} on XXXX and XX/XX/XXXX its here and when I logged in today still the same! showing that I'm late one month, that I have to pay XXXX, 2 late fees in there and a big mess! I called again today and after being on the phone with 3 different representatives I was unable to solve the problem. I was told that I owe around {$1400.00} just to place the account on-time. I have no idea what this company is doing, but its very frustrating that they do an agreement with a customer and now after we did a big sacrifice to do all the payments in time and correctly we are facing this and we have nothing else to do, no one is willing to help over there, we even have a newborn and we did everything possible to pay all the 12 payments as we did on time with the hope of having the account in good standing, they also, has been reporting us to the credit bureau unfairly during this time, and our account is still late and in a big mess. 
Attached is the copy of the repayment plan agreement and all the payments taken from them from my bank account, the 12 payments of {$1000.00} per agreement and the XXXX and XX/XX/XXXX regular payments as well, if necessary I can provide my full bank statements.