You are right, you don't have to take the English test if you were a Qualifying Work Permit holder and then switched to T2G. Qualifying Work Permit Holder means a Work Permit Holder who was issued a work permit in the business and commercial or sports and entertainment work permit categories.
28 November 2008 was the date when the Points Based System started and your T2G leave was granted in August 2009, i.e. after this date.
For the T2G extension application you don't need the KOL test.
Suggest you check that the CoS confirms that your job is at or above NQF level 3 and that your salary is at or above the appropriate rate for the job (para 194 and onwards in the T2 policy guidance):
http://www.ukba.homeoffice.gov.uk/sitec ... e2012-cop/
Check the completed application form very carefully before you submit it and if you pay the fee by card make sure that there are sufficient funds in the account. Payment is usually taken very soon after they receive the application.
Remember, only submit ORIGINAL documents, not copies.
If the sponsor hasn't certified maintenance (which you can check from the CoS) you will need to submit documents as evidence of personal savings. See para 153 onwards in the T2 policy guidance.