Bury your evil deed by doing good deeds.
When you're offering help, don't expect anything in return (e.g. payment, recognition or a word of thanks). Do it sincerely for the sake of Allah.
If you have asked Allah for assistance, and Allah sends it to you, don't be choosy. Whatever opportunity comes your way, we should thank Allah and do our best, and improve ourselves.
رَبِّ إِنِّي لِمَا أَنزَلْتَ إِلَيَّ مِنْ خَيْرٍ فَقِيرٌ
"O my Lord! truly am I in (desperate) need of any good that Thou dost send me!"
From Surah Al-Qasas 28:24