Srilankan Airlines — membership category

My name is dcr rajan and my flysmiles no is ul[protected]
I traveled to india for a wedding on[protected] and returned on[protected] via madurai airport
I am silver card member and have amex card as well as standard chartered card srilankan airlines platinum card
At the madurai airport the checking in officer informed me that according to the system i am a classic member and not entitled to addl 12 kg baggage allowance. I showed him both my credit cards but he insisted that he is only a checking in officer and he can only go by what is in the system and he cannot help me in anyway.
I need not pay such high card fees and be refused what i am entitled for
I have to go for weddings in june and august this year and do not wish to have the same sour experience back again

In these circumstances please change my membership to silver in the system to avert unnecessary issues at the madurai/chennai airports
Thanks and regards, rajan dcr