how can i retrieve all contact nos?

Question

I just restore my mobile phone to factory setting all my contact numbers were deleted. All of them are stored in its sim card.

Answer 1

If you did not have them backed up elsewhere and your SIM card was earsed, they are not recoverable.

Please remember to never keep any important files or data on only one piece of media. You should always have multiple copies of anything important. It isn't a question of "if" you will have an event which will lose data, it is only a question of "when" it is going to happen as, happen it will.