Regarding recovery of debt

I sold some material to a customer for which he gave me a cheque for payment. and the transaction continued for one year. after that he started avoiding my payment and later on he started bluffing me that aaj hojayega kal hojayega. later on saturday he came and again started bluffing me. i took a step. in same hour i went to his shop and took the material which i supplied to him. he was present when the material was loaded in my vehicle. after that he complained in front of t.i thana that i am very poor and i had intention of paying back but he took my material a which doesn't belong to me even. later on thana incharge told me to give him some time like one month and give back his material and also he will provide me a fresh cheque for my balance amount as same incident happen last night also. another shopkeeper also tried same but that person called police at that time and same agreement was composed. i insisted the inspector plz tell him to make payment in installment and he agreed for the same. after 3 weeks i went to thana as i havnt recieved any installment the inspector told me let wait till one month then will see. One Month is getting over on 9th July. What should I do there after if i dont get my payment. I even doubt on inspector that he took bribe from the that person and giving fake commitments