iphone 5

Please clarify "stuck"

You are most likely referring to the activation lock

Find My iPhone Activation Lock - Apple Support

Turn off Find My iPhone Activation Lock - Apple Support

That is an anti theft device and cannot be removed without the prior owner's consent and co operation

Contact the prior owner and have them remove the lock per this article

What to do before selling or giving away your iPhone, iPad, or iPod touch - Apple Support

If they cannot or will not - return the phone as it is of no use to you

If you bought it on E Bay - you may have buyer protection especially if the owner told you it was unlocked

Talk to E Bay customer service - hopefully you will get your money back

Next time you want to buy a second hand phone - please ask for the IMEI in advance and check it here first - the seller if legitimate - should not have a problem with that request

Check Activation Lock Status - iCloud