10 Year ILR Route Advise Needed

[SUKEB]

Hello Gurus,
I am making this enquiry on behalf of a friend who received a very sad news today regarding T1 Ent extension. Here is his timeline
Student visa SEP 09 to Feb 11
Post study visa Feb 11 to Feb 13
T1 Ent initial application made Feb 13 approved June 14 - June 17
T1 Ent extension made in June 17 and was refused in Jan 18 (accountant error)
Reapplied for Ext Jan 18 and got interviewed in March 19
Received rejection today on grounds that business activities isn't genuine.

Given AR to be submitted within 14 days
10 years due 29 August
All applications made in time

Please gurus can you advise on the best way possible to get to "over the line" for 10 years route.
I don't want to make any silly mistakes.
Whilst thanking you ALL in anticipation.

[zimba]

He has been an overstayer since Jan 2018 which means he does not have 10 years of lawful stay and is not be eligible as he is yet to regularise his stay. He better fight the refusal.