Q: How do I restore back my sim card contacts backed on my iphone 5

I went to get a sim swap to upgrade from 3G to 4G sim card from my service provider. During the process contacts from my older sim card were backed up on the phone and when the process was complete the person helping me did not remember to restore contacts backed on the phone back to the sim card. I am seeking help on how I can restore the contacts backed up on the phone back to the new sim card. I will greatly apprecaite any help on how to go about this.