Product: Mortgage

RE : NationStar Mortgage Customer over 5 years residential mortgage with company and I am a senior citizen. 
Nationstar Mortgage sent me several letters, phone calls ( for one year ) to refinance promise lower interest rate and no money to refinance. I will be XXXX XX/XX/XXXX so the lower interest rate with XXXX $ lower monthly payments attracted me, because now at retirement I would be able to continue to pay my mortgage. 
I pay for my taxes, PMI and house insurance into the escrow account that is included in with my mortgage payments. 
Believing all that written and promised during my interview with Nationstar Mortgage I agreed to refinance. ( 30yr fixed 3.375 interest rate and XXXX monthly payment which included escrow amount-FHA Streamline loan which would make my monthly mortgage rate decrease by {$430.00} from my previous ) Before closing I was contacted by Nationstar and was instructed that I would need to bring {$520.00} check to closing attorney ( all during my transactions with Nationstar I was promised no monies at closing ). On the day of closing I was informed that I would need to bring an additional {$610.00} added to the XXXX because my city/county tax department said I had late payments that needed to be cleared before closing ( when my city tax/county department was finally able to check they informed me I was not behind in any taxes and Nationstar would need to send in writing that they were informed of this. I was on my way to the attorney for closing and I was pressured by Nationstar that I would lose the lower interest rate if closing delayed and I did not pay the {$1100.00}. So I felt that I had no choice but to pay. 
I closed with attorney on XX/XX/XXXX for closing and the percentage rate as well as monthly Mortgage payments had not changed. I was informed by the attorney that my old mortgage would be paid off as well as any payments connected to the old mortgage. My last correspondence from Nationstar stated that my escrow from my old loan was {$3500.00}. Each year that was used to pay insurance, taxes. 

On XX/XX/XXXX. I received a letter from Nationstar stating that I had an escrow shortage on my new loan? I was also informed my NEW monthly mortgage payments would be {$1800.00} to cover shortage spread? 
I called many times to Nationstar. Last call on XXXX to inquire regarding shortage since my loan was new and all payments disbursements should have been taken care of with the closing of my old loan that had enough monies for disbursements. I was informed that {$3000.00} was the shortage. Also the Manager stated that it " looks like '' my escrow monies from my old loan were used " for something ''. Now I was being asked to pay my old loan XX/XX/XXXX escrow back to Nationstar. Also the {$610.00} could not be explained nor did Nationstar want to discuss. Finally on this call the Manager that I spoke with said some of the monies " missing '' were put back into my new loan escrow, so now the monthly payments to cover the " shortage spread '' and my current mortgage payments would be {$1700.00}. 
Why was my escrow monies from my old loan not used to pay the old loan XX/XX/XXXX disbursements? Why am I being asked to pay my old loan XX/XX/XXXX escrow monies again? 
Also the {$610.00} that Nationstar states was from old back taxes was not confirmed by my city/county tax department and they also deny any shortage was reported to Nationstar.