I was served with a summons and responded by agreeing to payment arrangements. After 6 months of payment arrangements they entered a judgement and judgement was granted. Is it legal not to provide me with a court date?

You say you responded to the plaintiff. Did you ever respond to the court that issued the summons? If not, then you screwed yourself. By not responding they were able to get a default judgement. You MIGHT be able to vacate the judgement by showing you were never informed of a court date and that you thought, by agreeing to a payment plane, you were forestalling litigation. But it's a longshot.

Was there not a date on the "summons" ?