Bank Draft / Check

No this is not a good idea because they will try to draft from it and if there is no money then you will be hit with fees from the bank and Zwicker will hit you with returned check fees and say you voided the agreement.

Tell them that you will pay by money orders only. Preferably Post Office because they are cheap and can be tracked.

I fully agree with cellular. The only reason they insist upon that information is so that they can hit the account when they want for whatever amount they want. You may be protected if you have a full agreement in writing listing exactly when debits will be made and for how much, but I bet they never sent you any such thing. I would be VERY wary at this point.

Send them a letter outlining the agreement you reached with them. Also enclose the first payment (money order) with the stipulation on it and in the letter that by cashing it they agree to the terms set forth. Now, technically in some states having anything written on the money order won't enforce it, but you mostly want to have a written record if they violate that you can use in court. Be sure you send this by certified mail return reciept and keep that receipt in a safe place.