Product: Mortgage

Roundpoint Mortgage has made several mistakes over the course of XX/XX/XXXX and XX/XX/XXXX. 
I wont go into details since this is my third complaint but to recap they have failed to calculate our property taxes properly ( 50 % off - according to them they had the wrong parcel number??? ), they lowered our monthly mortgage and sent us a refund check of {$2600.00}, and despite our concerns said it was correct and that there would be enough to pay taxes, PMI and Hazard insurance. 
We in the process asked for a new analysis which took 4 months to get and early in the process realized that they had never paid PMI. WE notified them of that error and were not aware they had not been paying. PMI is their requirement in order to protect THEM since we didnt put 20 % down. They failed to pay this and for about 18 months used the {$100.00} a month we put toward PMI to go toward property taxes. 
In summary This all resulted in a {$4000.00} shortage in escrow ... .an increase of {$500.00} payment a month. Since we were assured the refund check of {$2600.00} was correct, we have used towards other financial obligations. 
So now, where are we supposed to find an additional {$500.00} a month for mortgage? 
A variance of {$100.00} or so is normal and to be expected but this is unheard of and all because of mistakes after mistakes they made and a lack of communication. 

In XX/XX/XXXX, 2 months after our first complaint we finally got a letter from them, finding excuses about all the mistakes they made and letting us know that they used over {$2000.00} of our money in the escrow account that we had put toward XX/XX/XXXX property taxes. There was no communication or discussion around it. Just we took your money, increased your payment and now you have a shortage. Of {$4000.00}. The claim that they have tried to reinstate PMI many times in XX/XX/XXXX and in XX/XX/XXXX - yet we have never even heard that there an issue with PMI and that it hadn't be paid until we realized it in early XX/XX/XXXX. We have asked several time for proof of this attempt to reinstate it in XX/XX/XXXX after they realized they hadn't paid it and that it got cancelled..apparently they didnt have proof of employment from us?? again..we never got contacted on that matter and asked proof ... .. we also asked proof regarding that approximately {$2000.00} payment they made from our escrow account to reinstate PMI in XX/XX/XXXX ... cause yes now they had to pay 18 months of monthly premium in order to reinstate ... again where is the proof that this is what you did with our money??? NONE ... .and we have asked. We called the PMI provider and they couldnt provide information since RoundPoint is there customer but did agree we are totally in the right to request proof of payment and proof of all these attempted reinstatement in XX/XX/XXXX. Roundpoint is such a fraud and there is no one that can communicate with you. We finally got answers after we filed a complaint here. Then we got an email and phone number of a consumer advocate - we got a few emails and I was hopeful- then, our payment mortage got updated on the website, still no answers on all the proof we are requiring, and the person no longer answers emails nor the phone ... ..?? goes straight to voicemail.How is this company legit - i see I am far from being the only person complaining about similar issues with them!! In their formal responses, the only thing roundpoint agreed to do is to spread the shortage over 36 months ... which still leaves in with an increase of {$300.00} a month!! and no proof of where our money went!!