Sounds like the agents may have paid too little attention - we gave up using agents decades ago because they were so disappointing. My leaning is toward what others have said, unreliable tenants best got rid of soonest. On the other hand, your husband may have the correct attitude because the situation is now set and there is nothing to do but wait until you can get rid of them - unless they unexpectedly surprise you by turning out fine. Sadly, there seem to be lots of tenants who take the attitude that no matter how good the property, how low the rent and how reasonable the landlord is, they are being exploited and must try all they can to get their money's worth. Nobody, absolutely nobody, has any sympathy for landlords.