Home Loan not properly assessed - Poor support

I have app**** for additional funds from my current home loan. A value for less than what I was requested was approved based on an assessment which after investigation and providing proof of an unfair assessment has not been reviewed. I am very disappointed in Standard Bank, who I have been a loyal customer for over 10 years now. I have done a comparative analyses and justified the value which I believe and have evidence that the amount requested is fair. I have requested and escalation of the matter and sent through emails but no response.<br> Why cant standard Bank grant me my request based on this ?