It seems i have already replied the question in another topic. still for brevity, i might just state here that the matter may be a civil dispute, however, even in civil disputes there is a tinch of criminal offences committed, like criminal misappropriation of property, criminal breach of trust, etc.
The role of an advocate here is to see that the client gets relief / justice and adequate punishment is metted to the offender.
In your case, by a clever drafting, inorder to coerce the other party to perform his part of the obligation, a criminal case can be made out, hence the call for a lawyer.
Hope it suffices your query.