Dunkin' Donuts review: Coffee - amount, customer service

I purchased coffee via drive through. When I took the lid off the coffee level was more than an inch from the top.

I contacted Dunkin Donuts corporate. They referred me to owner who snet me this email:

From: Rambhai Patel
Sent: Thursday, 16 January, 2020 12:20 PM
To: [Redacted]
Subject: Fw: DBI Case #[protected] - Guest Contact: Small Product - PC #340453-DD [ ref:_00Df44mQE5._5002T1CGzAw:ref ]

We apologize for the product issue that you experienced and we would like to offer you a free Extra Large Hot or Iced Coffee if you would allow our team to serve you again. In order to receive this offer please visit the store and either show them or print this email so my team can honor this offer for you.
Thank you,
Ram Patel
Subject: DBI Case #[protected] - Guest Contact: Small Product - PC #340453-DD [ ref:_00Df44mQE5._5002T1CGzAw:ref ]

Howver when I took the email to the store they refused to honor it and now now the owner doesn't respond to my emails.