Need Some Advice

[wychiu]

Hello,
I moved out of my apt and i have a subtenant living there. the ll does not like the subtenant because he is suing the ll. there is a whole story behind this that i will not get into. the ll just sent me a letter telling me because i vacated the apt, the ll is cancelling my lease. he used the word "cancel" i sent via mail a check for june's rent. i think i can cancel the check if i want to. should i cancel the check? and if i do not cancel the check, can i get my money back for june? also, i prepaid july because it was on the lease. can i get back the money for july also?

thank you