there is a concept of 'verify payment'
pls. check it out in 'services' menu after login
in case money gets debited from your accounts in sbi, indian bank etc., then u can click on the link provided therein so that the status of the srn gets changed to 'paid';
so if the portal is slow, better pay through the stipulated banks so that your payment is secure
further, always generate a pay later challan and then make payment through credit card / internet banking. dont directly pay;
by doing this you have a paylater challan in hand just in case payment gets bounced, you can always raise a ticket or use 'verify payment' optio
regards,
yogan.