Product: Mortgage

I, XXXX XXXX am located in XXXX California. I originally received collection phone calls and letters from JG Wentworth (JG) (mortgage payment) for non-payment of XXXX and late fee notice. My XXXX   payment of XXXX (in full) was submitted on XX/XX/XXXX. I use scheduled bill payment with my bank which disperses cashiers checks to JG Wentworth each and every month automatically. Upon calling my bank, I learned that JG deposited my cashiers check of XXXX on XX/XX/XXXX. My bank sent me proof of payment which I submitted to JG on XX/XX/XXXX and received confirmation of incident.#XXXX. I called JG on XX/XX/XXXX 2 different times as well to discuss. They agree after reviewing my proof of payment that the XXXX payment was received and processed but they do not know where it was applied.  I called on XX/XX/XXXX and was told that it appeared to be resolved but didn't show "closed" but should receive confirmation email it is closed that night. I did not receive an email or any information regarding the lost payment but rather information on how to change my married name.  I responded to the email asking about the lost XXXX   payment which was my concern submitted. I called JG on XX/XX/XXXX explaining that I was told the incident was closed/resolved and should have gotten a confirmation email but didn't. The operator told me I was given a new "incident" number XXXX and was told they have given themselves until XX/XX/XXXX to resolve.  I called XX/XX/XXXX and the operator (XXXX XXXX) was very sympathetic to the problem stating he understood my frustration and that I have done everything I am supposed to. He also stated that a payment had applied to XXXX but that now XXXX and the late fees/interest from XXXX remain due. The monies applied to XXXX was my XXXX payment submitted. XXXX agreed the original XXXX  payment remains lost and he submitted an "urgent/priority" request that he stated should be resolved in 24 to 48 hours. I called JG on XX/XX/XXXX still unresolved. I demanded to talk to a supervisor. In talking with him (XXXX), he stated that he can see the urgent request was submitted by XXXX and they have given them a new date to resolve by XX/XX/XXXX. I asked for the incident number assigned because they just assign new numbers and extend their date to resolve. He refused to give me a new number or deny that their wasn't a new number. This became a very heated conversation on my end. I told him I was going to pursue this further. The same exact thing happened to me last year in XXXX  and it took many many calls, frustration and 3 months to resolve. I threatened FTC, your dept and an attorney for this frustration. I told him they are in no hurry to find my payment because they are drawing interest as it sits and I am sure they have many more like me, illegal service.
So, here it is the XXXX and my payment has not been found. I did not call yet, I checked my account and found the outstanding amount still due. 
In the meantime, I'm receiving mortgage payment assistance notices, calls from their collection department due to my "failure to meet obligations".

I'm nervous about the mortgage company moving forward with foreclosure proceedings or filing negative reports against my credit.

Thank you in advance.