Warranty that no dealer wants to honor

I went to the Midrand branch a couple of months ago to test my battery as it kept on failing and it was said that it requires a replacement because the health was bad. I pointed out that the warranty is still valid as it was purchased in Jan 24 and has a three year warranty. They stopped being helpful because they wanted me to purchase a new battery instead of a warranty claim saying that they needed the original invoice for the purchase which is impossible as I purchased the vehicle with the battery already there. I then left and about a month ago, I went to the waterfall ( midrand ) branch with the same exercise and they directed me to the same Midrand branch mentioned above.

It is not right that one of first battery center's selling propositions is a warranty that clearly no dealer wants to honor