help me!

the story:
i wrote a check to my landlady for july's rent and somehow misplaed it, i thought in my room. already being voerdue, i just wrote out another check rather than look for hte first, and gave it to her. next time iwent to the bank, my balance seemed too low, so i checked and saw that both chekcs had been cashed. my landlady sweras not by her, so by whom?
i called the bank right away and the south-asian tele-help person was totally useless. well, wahtever, he "filed an investigation" or some such. i called again today and they read me the letter that has allegedly been sent to my home, with a copy of said check, requiring me to file an affidavit and some notarized form and then they'll see what they can do.
since the bank seemed wholly uninterested in what actually happened to the money, as well as since they're probably not really interested in helping me not lose money if its at their expense, i called the police.
the police will file a report of theft if i come in to the precint with a copy of the check, but it's entirely uncelar what that will do, besides maybe make it easier for me to yell at the bank.
so yeah, advice or assistance, especially from the legally inclined or otherwise argumentative, is welcome...

the obvious caveats: yes, i am a disroganized idiot but no, that doesn't mean someone can steal from me. I also do not have time for this right now...