I bought a iPhone SE on eBay locked and it did not come with a sim card? Why is this?

I bought a iPhone SE on eBay locked and it did not come with a sim card? Why is this?

A SIM card is what links a phone to someone's phone number.

Presumably the previous owner kept the number and used the SIM in another phone.

Any of the major networks will gladly give you a SIM and set you up on a plan.

As for the phone being locked, if it belonged to the seller ask them for help to unlock it - if they won't or can't then file a dispute with ebay!

The ad should have said something like: Locked to Three. Locked to Virgin. Locked to EE etc. You then buy a SIM which is linked to the locked network.

You failed to look at all the conditions of sale, or the seller failed to mention those facts. Indeed, in private sales, people generally hang on to their SIM card and use it in their new phone.

Why would it come with a SIM card? SIM cards come form the service provider.
If you bought it to use as an iPod Touch, you might have to borrow a SIM card form another phone long enough to set the phone up for your use. Judging by the telling me it has no SIM when I turn it on on the iPhone 6 I use as an iPod Touch. I only need the SIM form my other phone long enough to set it up unless I decide I want mobile data and phone calls for it.

You need to get the SIM from your service provider.