Product: Mortgage

We purchased our home in XX/XX/XXXX. 
When the escrow portion of the payments were set up the annual county property portion was based on what the previous owner had been paying, {$4100.00}, however before my first mortgage payment, in XX/XX/XXXX, I emailed our mortgage company to inform them that I'd like them to adjust our payment to reflect what our property taxes would be, {$1800.00}, due to an over 62 years of age county tax exemption I was receiving. They responded that before they could make an adjustment they'd need to see a property tax assessment document from the XXXX County tax assessor. 
We received that document and promptly phoned Amerihome customer service to request an escrow adjustment and was told they had the property tax document and would soon make the appropriate adjustment. 
When this hadn't happened after a couple of months I called back and was informed " yes, we see your new mortgage payment will be reduces from the current {$2700.00} to {$2400.00}. I thanked them and adjusted my payments accordingly, but began getting letters stating that these adjusted payments would not be accepted and that I needed to pay {$2700.00}. I again called customer service who looked at my account information and again informed me that I should only be paying {$2400.00} and that I could disregard the letters asking me to pay {$2700.00}. 
This went on for two months during which time a received a few for letters and emails, increasingly forceful in tone, asking that I remit arrears payments of {$2700.00}. 
I again called Amerihome customer service to ask what the deal was and did their various departments ever speak to one another and/or share information. I was told they'd look into it but in the meantime I sent in the requested payments of {$2700.00}. 
On XX/XX/XXXX I spoke with XXXX in customer service who told me everything was resolved and that an escrow overage check for {$1700.00} was on its way to me, in fact I received a letter with a photo of said check ( attached ) and payment adjustments but no actual check. 
When I called customer service again to ask where the actual check was I was told I'd need to call the escrow department to get this all straightened out. 
I called the escrow department and the woman I spoke to there told me that she had no idea why I'd been told by 5 times by various Amerihome customer service reps that my escrow payment would be adjusted because there was no way that was going to happen until they did their annual escrow assessment, which was still some months away. 
We continued to make our {$2700.00} payments, based on an erroneous property tax bill of {$4100.00}, hoping that when they actually paid our property tax someone would notice that is was {$3000.00} less that what they thought it would be but this wasn't to be. 
In early XXXX of this year we received a letter from Amerihome informing us that as of XX/XX/XXXX XXXX would be our new loan servicing company. 
I subsequently phoned Amerihome customer service and spoke with XXXX, gave her a condensed version of all the nonsense we'd gone through over our escrow account, and asked if she'd please correct their mistake and not pass in on to XXXX. She said she could and would, that our new payment amount starting XX/XX/XXXX would be {$2500.00} and that near the end of XXXX we'd be receiving an escrow overage refund check in the amount of {$3200.00}. Hooray! 
However ... It's now XX/XX/XXXX, we haven't received our escrow overage check, and XXXX is refusing to accept the XX/XX/XXXX payment we made, demanding {$2700.00} instead! 
We feel like we're in the Twilight Zone! Please help us resolve this seemingly never-ending loop of incompetence we're trapped in.