All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Throwing the pebbles whether it is the greater pebbles on 'Eed day, or the throwing of the three pebbles during the three days that follow that, is one of the obligations of Hajj. Not throwing the pebbles does not invalidate Hajj but one has to offer a sacrifice. The questioner did not clarify to us which pebbles he threw but did not fall in the basin; was it the greater pebbles on 'Eed day or all the pebbles? The scholars differed in relation to the ruling about not throwing the pebbles, however, they all agreed that it is not sufficient if the pebbles did not fall in the basin.
In our view, in your case, a sacrifice has to be offered by each one of you. So one sheep or one seventh of a cow or a camel has to be offered on behalf of each one of you in Makkah, and it should be distributed to the poor there.
Allaah knows best.