Is expiation required for one who intended 'Umrah upon arriving in Makkah, then delayed the Ihram, Tawaf, and Sa'i until the following morning?

You made a mistake by taking off your ihram garments and wearing sewn clothes. If you were unaware of the ruling, then there is nothing upon you. However, if you knew of the prohibition, then repentance is obligatory upon you, and you owe the fidyah, which is fasting for three days, or feeding six poor persons, or sacrificing a sheep.