Hi, i have lost some contacts in sim swap? how to restore

Hi, Recentlyl i went to BSNL cusotmer care centre to migrate to 4g. They have done that . While all others, like STV, Plan balances and all others are not affected, some contacts, i stored in the phone have been lost.
Will sim swap, erase the contacts stored in old sim
If not , what would have been the cause for this.
i do not say, that all contacts are lost, but i do find some contacts are lost after sim swap.
This i also noticed in the other sim, where most of the contacts have been lost.
My phone is samsung smart phone and the other phone is basic phone.
Could some one throw light on this
Once sim swap has been done, the old sim could not be used. i got Sim not registered error.
experts please say the solution.

Maybe some contacts were stored on the sim card. If you still have the old sim card, you can put it in a feature phone and access the contacts, even if it shows no service. Just a word of advice, since you have a smartphone, you might want to sync contacts to your Google account. That way, you won't lose contacts while changing your phone or during a sim swap.

put old sim in phone.
Copy all contacts from sim to phone (there should be an option for this).
Remove sim and use new sim.
If you have dual sim option then it will be even more easy.

Hi, Crazy and smh
Thanks for your advices. i got the old sim. The phone has duo sims. Just copied the contacts without any loss.
Thanks for the answer

Why would you store contacts in SIM? Always keep a copy of them in your phone and sync them with Google or iCloud.

on featurephones, the smarter thing is to store contacts on the sim card.

rajujayaraman said:

My phone is samsung smart phone and the other phone is basic phone.

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I feel he is moving to Samsung now which is very much capable of doing what I recommended.

ajgamer said:

Why would you store contacts in SIM? Always keep a copy of them in your phone and sync them with Google or iCloud.

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