please anyone with an idea of how to submit an administrative review. the email required for the abuja embassy and procedure involved. thanks

Hi House... I am a phd student in the UK I made an application for my spouse under the tier 4 dependant category and just got the passport back with a refusal letter stating that the required funds of 4140 pounds was not held for 28 days. I have established presence in the UK and the required sum should be two months depandant maintenance only which is 920Pounds. This is an error on the part of the ECO and I would love to know how to send a request for an administrative review. is it by email? if so which address? The refusal letter only came with a letter of appeal and I know the process takes time, I'm opting for the shorter administrative review. I would appreciate any helpful comments