Domino’s Pizza complaint: Late delivery complaint and subsequent falsification by store manager

I ordered online on 19th june 2021. The order was delivered late. When queried about 30 min delivery guarantee, the delivery boy rudely informed that is not available any more. I lodged a complaint online on dominos app and the automated message acknowledge 6 min late delivery. I have the message trace with me.
Next day store manager called and tried to enforce invalid justification. Some examples – 1. He told me it was delayed due to water logging. I told him there was no water logging on the route from the store and my home. I also told him the order was despatched late from the store itself. I was tracking it. 2. He told me they were informing all customer during order placement that the guarantee cannot be given. I told him no one has contacted and informed me. I asked him to tell me if Dominos has stopped the guarantee or not. He avoided a direct response and finally told me he will speak with the delivery boy and take a call.
Afterwards, when I checked the order details, i found the delivery time was manually changed to 29 mins and now this change invalidates my original complaint.
I have all the traces of my chat with their online bot and also an sms acknowledging the late delivery.
I found it unethical from his part and want to bring this issue to the notice of higher authority within Dominos. This is an respected brand and I’m availing their services for many years now. I think these kind of unethical behavior and unacceptable service will not be good for the brand image if allowed to be continued. This is not just a matter of Rs 300 guarantee. Hopefully someone will recognize the rot and take appropriate actions against the persons involved.
Thank you.