You'll need more than the charge amount due to foreign
exchange fees and international excise taxes.
If still declined, call Pearson customer service (or email) and ask why.
I play Eve Online, and every year, I am recurred-billed for the subscription fee. Eve (CCP) is located in Iceland. My bank is in US. Recurred fee is $134.00 and my bank adds $12.95 excise tax and $1.95 international service fee. SO my $134 charge turned into $158.90.
You may need to add an extra $50 worth of rupees to your account. Current exchange rate is 60 rupees to dollar. Means you may need 12,000 rupees in your account to cover the charge.