Please help me with this letter sound more professional.... Thanks!!!?

To whom it may concern, I Maricruz Huskanovic made a personal loan of $2,000 to my sister Carmen Chavarria on January 2008, We agreed she would pay me back as soon she recieved her Income Tax refund. She gave me a check on March 28th which was deposited in my washington mutual account on March 31st of 2008. Please feel free to contact me if you have any further questions.