High assessed customs value for postal import, help please

I have bought an car security system (remote lock) from www.aliexpress.com , china, its actual price is about USD 25, after discount i paid USD 21.9, by credit card, But once i got it through customs, the Postal appraising division, (PAD) chennai, have assessed higher value of Rs.6000 and on that 41.4% duty comes to Rs. 2530,

I am shocked to see, the duty , double the original cost.

actual cost i paid                                      - Rs.1300 approx

value assessed by appraising offcier  - Rs.6000

Duty have to be paid                               - Rs.2530

I have got this memo from post office, but i sent back for re- assessment to PAD, foreign post, chennai, with all supporting documents to prove it is only Rs.1300,

1, Credit card statement copy

2. order form from online page

3. Actual price displayed in the website

4. My PAN copy

etc. and also the same product with well known brand name will be available in india for about Rs.2500-3000 maximum, that too with warranty,

it was there in office for about 2 months and after, But the parcel came back to me today with same duty, as before. i am confused whether to pay duty and claim back, or file a suit against customs officer, since i have all things to prove the price is just Rs.1300, please help

I am much frustrated with PAD, since they charge much higher, and also not accepting the documents as proof, i dont know , on which basis they assess value,

Is there any legal solution to this? or by RTI? i came to know that chennai surface PAD, does charge more to most people, but i do not want this to happen to any other.