Sister's dependent visa refused

[makiz63]

I applied for a dependent visa for my sister who is 19 years she lives in Africa, I have Indefinate Leave to Remain in UK. The reason for the refusal says "under section 297 and 317 of the Immigration Act, I am not satisfied that you are under the age of 18 or that you are living alone oustide the uK in the most exceptional compassionate circumstances and are maily dependent financially on relatives in the UK".

We were given 28 days to appeal but we are only left with a week from the date the letter is dates.

Please can you advise of any ideas as I am trying to draft the letter of appeal.

Many thanks