LOANER won't allow to return closed checks which we paid online!!!

Hi, I need an advice regarding this company who provides credit without collateral. We applied for personal loan and it was granted. As standard procedure, we gave 24 PDC (post-dated checks). Our transactions are good for the first few months. However, my wife closed our checking account due to missing checks. We notified this company about the situation. The company said that we need to pay for additional Php200.00 on top of our monthly due to closed checks. So we agreed to pay what they have demanded. After almost 10 payments, we decided to get those checks that we already paid online. This company refused to return the checks which are supposed to be paid already. Is this legal? What we are just requesting is for the company to return those closed checks which we paid online. We said that we will not pay the company until they have given us the checks which we think are rightfully ours. Please advise. Thanks.

Any body who cares to answer my query? Thanks.