Bad attitude

On the 15th March my car battery was replaced at Best Drive Constantia, where I had bought it on the 18th May 2021. It had a 2 year warranty. Today on the 13th April, I received a call from Best Drive saying Willard Batteries, alleges that the battery that I exchanged, was 2 months overdue for replacement. A simple question is, it took Willard Batteries almost a month to allege that the battery that I took in was wrong. What doesn't make sense is I took in my battery because it was not charging . This is ridiculous. I have a receipt to prove purchase of my car battery.