antifreeze is leaking on 1998 Volvo V70

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Replace heater core anti freeze is still leaking on the floor of the passenger back seat carpet is drenched. Don't know where it's coming from.
(3) Answers
Very likely the junction where the core is connected to the coolant pipes. There are o-rings and seals that need to be removed and installed properly. Also, if there any scratches in the junction housing it will leak.
1.Heater core drain not connected properly.
2.Heater core is defective.
3.Heater core connectors are in poor condition.
4.Tech didn't recheck after the repair.
agree w/ S/B imports-only choices- heater core damaged upon installation/poor heater hose connection or use of auto zone heater core.