How can I appeal against granted FLR on the 10 years

[ashaalan]

Hi
I have granted an entry clearance visa on 2013 as I am spouse of a British citizen and a father for a British child.
On may 2016 I've applied to extend my stay using the FLR(M) form and depending on cash saving to meet the financial requirements.
The main amount I depending on was held as investment certificates in my bank account at my country and I provided a bank letter from the bank stated the amount and the period the certificate held under my name and the date it has been liquidated to my account.
After 7 weeks I received a letter from HO as the caseworker requested more evidence regarding this fund such as bank statements and portfolio report for this fund or other relevant documentation.
I got the bank statement from my bank but I couldn’t get this portfolio as this certificate was an internal transaction on my account.
I explained that to the caseworker in a letter and asked him to use the earlier bank letter as it was clearly confirm the date I held this fund. Then sent it with the bank statement which he requested.
Today I received his decision that I failed to provide evidence to the time I held my funds and he cannot accept my cash evidence therefore I don’t meet E-LTRP.3.1. But consideration has been given to my British children so he will use the exception in paragraph EX.1 (a) and (b)
And I've been granted 30 months leave under D-LTRP.1.2 which mean I will be on the ten years rout.
Also I've received the BRP card with expiry date not related to the decision or the application date
The letter I've received doesn’t explain what to do if I am not happy with the decision.

Would you advice what to do in this case.

[vinny]

Request reconsideration.