Sqft discrepancy on appraisal report

[Homer Rodriguez]

My wife and I are under contract for a home in the Houston area. We made an offer 25k over list as the Houston market is insane and houses are getting many offers within a day. Everything was on track. Inspection went well Bank was good to go then we got the appraisal back. 15k low. Looking at the report the appraiser said he used the appraisal district for his dimensions. Well the district has the house at 2917sqft but he has the house at 2600sqft. This is 100% why it didn’t appraise. We sent the appraiser several houses in the same neighborhood with the same floor plan showing the house to be the 2917sqft. On top of that he used comps that weren’t recent sales when there are several houses that have closed in the area within the past month. Of the 5 comps he used only 1 was a sale the others were just houses he picked from the neighborhood and adjusted the value on. It appears he isn’t going to budge on his appraisal even though he said he used the appraisal district and he doesn’t have the same sqft as they have. The seller isn’t coming down as they had cash offers from investors and are willing to put the house back on the market so they claim. We are a week away from closing. Should we ask for another appraisal or should we walk from this deal. It’s hard to say if the seller is trying to call our bluff on walking. Is there any other way to try to convince the appraiser to change his appraisal? Any help would be appreciated. We didn’t waive appraisal so we can walk and get our Earnest money back thankfully.