So many red flags and you ignored every single one. While i empathize with you having to deal with this kind of couple, i must say you drove yourself right into a ditch.

It is for these reasons and many more that i adhere to the following terms for weddings - contracts and deadlines - premium price point. Couples respect a higher paid dj way more than djs that do 500-1000 pckgs. - couples are expected to figure out all light, sound, production.i show up with a laptop. No mcing unless they pay more and i do an agreed # of hours. - never emotionally respond to a customer. The cheaper they are , the more chances they act entitled. I personally wouldve walked away even in the middle of the wedding. You let them cross the line multiple times. You were doing them a favor.

Stay positive. Do good work! Dont feed into negativity