When Jesus Christ died for you, all your sins—without exception—were placed on Him, and He took upon Himself the judgment you deserved. The Bible says, "When you were dead in your sins ... God made you alive with Christ. He forgave us all our sins" (Colossians 2:13).
One way we know we've truly given our lives to Christ, however, is that we regret the wrong things we once did, and if possible we want to make them right. Yes, God has forgiven all your sins, but He also wants you to do whatever you can to heal any hurts or undo any damage you've caused. God's will is for us to "make every effort to be found spotless, blameless and at peace with him" (2 Peter 3:14).
I often think of a man who met Jesus one day by the name of Zacchaeus. He apparently had grown very wealthy by cheating people while collecting taxes for the Roman government. But when he met Jesus, his attitude completely changed, and he was determined to reverse the wrongs he'd done. He declared, "Here and now I give half of my possessions to the poor, and if I have cheated anybody out of anything, I will pay back four times the amount" (Luke 19:8).
Since you can no longer repay the store owner, I suggest you make a special gift to your church or other ministry that will help others in the name of Christ.