Appraisers rent analysis low

[Michael Jones]

I've been going through mortgage hell trying to get a 60% mortgage on a currently rented house in Portland.  The appraisal came out fine for value but the appraiser estimated the rent to be $1900.  Rent is currently $2500.  I had no problem filling the vacancy in two days last November. 

 I've asked the appraiser to both explain his reasoning and to accept my provided comps for rent which shows rents in the $1900 range for smaller houses (in size and bed/bath combo's) and comps higher than my rents all the way up to $2900.  He refuses to even respond. 

The mortgage company underwriter will not move forward based on the appraisers opinion.  

So, they will not fund my loan however do I have any recourse?  I've provided proof of rents and lease agreement and the bank has chosen to rely on the appraisers opinion over my actual data and now I'm out $850 for a useless appraisal.  It's the banks prerogative to not fund but at the same time, am I not entitled to a refund for the appraisal?  I've performed and they've chosen to accept the opinion of the appraiser.  Any recourse?