For 18-Aug-14, as you are in gain of THB12,781,134, in that case (you changed side from loss to gain), so we must return all existing collateral to you not take MTA as consideration.
For 6-Oct-14, same case as above, but this time is HSBC change side (from loss to gain THB14,731,809) so we can call back all collateral without taking MTA into account.
Today case, as no outstanding collateral in both KRUNGTHAI and HSBC, call amount should exceed THB30m MTA.
You can see all above in csa agreement.
Wish above can clarify your query.