Black spot on screen

Based on your situation, I recommend service.

Service Checklist:

• iPhone service pricing.
• Check AppleCare Coverage.
• Get your iPhone ready for service.

Click ▶︎ Start a Service Request. ⚛️

Need more help?

• Call Apple Support at 1-800-APLCARE. 📞
• International Support. 🌐
• Contact Apple Support. 📝
• Live chat using Messages. 💬

Click ▶︎ Check Repair Status. 🔧

Your only hope is that it is still under warranty or under Apple Care, if not then it is going to be hard for you to prove that you did not drop it and get a free display replacement as genuine ones are quite expensive.