Anual allocation of cos expiry e mail from UKBA

, I wonder if someone could help me, please.
my employer got licence in August 2013, and initially requested just one unrestricted COS, this COS was then given to me and I have T2 (General) visa until 2016
my employer recieved 3 emails from the UKBA so far, saying, "Please be aware that XYZ's (company name) allocation of Confirmation of Acceptance for Studies/Certificate(s) of Sponsorship (CAS/CoS) in Tier 2 (General) is due to expire on 05-April-2014...If you are licensed in Tier 2 General and/or Tier 2 ICT and this allocation is due to expire, you can request an allocation of unrestricted CoS up to 3 months in advance of your allocation expiry date but your new allocation will only be available from the 6th April.You will also have the option to request next year's allocation in the other Tiers/categories in which you are licensed."

My questions are:
initially my employer requested only 1 COS, this has already been used. employer does not require anymore COS. What needs to be done in the SMS (Sponsorship Management System) to rectify this?

as I am an existing T2 (Gen) employee in the company, does the company always have to have 1 live COS allocated to keep my status valid?

I will need to renew my visa in 2016 December in another 2 years, I believe I will need my employer to allocate a new COS to me? in that case, shall the company request 1 COS every year until my renewal to be in the safe side?

Does anybody know about this?

look into tier2 section, this is already replied?