Yes, you may call a defendant as a witness and compel the defendant to testify in a civil case.
If you need this testimony to prove your case, you should have the clerk issue a subpoena for trial to the defendant and have that subpoena personally served by a process server upon that defendant (sometimes a witness fee, a mileage allowance, and a copy of the relevant statute must also be included in the package). There should be a standard court form available to do this. The subpoena to appear and testify at trial must be delivered to the defendant by the process server a certain amount of time in advance (usually two days, but court rules vary).
Also, when you call a defendant as a witness you may generally examine the witness with leading questions, which is something that you are not usually allowed to do with witnesses that you call in your own case.
Forcing a defendant to testify to the indisputable facts is a good way to meet your burden of proof towards establishing those facts. But, when you call a defendant as a witness, you should limit your questions to those you know the answer to and can ideally prove with other evidence if the defendant lies. Don't try to tell the entire story of the case with the defendant, just the undisputed facts.
The one narrow exception to this would be a criminal contempt of court proceeding (i.e. one seeking the remedy of throwing the offending party in jail where there is no way to obtain relief by taking the action requested) prosecuted by a party within a civil case, to which 5th Amendment protections would apply. But, this would not apply to the kind of case described in the original post.