Chase Card Services Moving due date up one week, with no notice, the one month I had heavy expenses (wedding) ripoff Wilmington Delaware

I've been a Chase customer many years and always paid my balance each month. When my husband and I got married last month, I put the cost of the reception on my Chase card because I knew the due date was mid-month, and I'd have enough money in the bank by then to pay off our wedding.

Chase turned out to be a wedding crasher! With no notice beforehand, Chase unilaterally moved up the due date. A week ago, I received my statement, later than usual. The last page of the statement said, "Please note that your payment due date has changed and is earlier than in previous months. To select a payment due that works best for you, please call customer service." They shortened my due date to six days from when I received the statement - and made the payment due about a week earlier than any previous due dates!

I called customer service, and the first guy said he could move the due date back by one day (not like that would have mattered). I then talked to a very rude supervisor (who said the first guy could not have said that) who was generally unhelpful.

I find it highly suspicious that, in the one month that I have a much higher-than-normal new balance, they happen to move up the due date? Do they have a pattern and practice of doing this? Do they have a computer program to tell them: this customer is having a high, outlier month, so let's find ways to sock it to her?
Any business that makes it a practice to find creative ways to rip off its customers - and then provides no help whatsoever, proving their ploy is intentional - is going to lose my business.

Newlywed
Austin, Texas
U.S.A.