The head of email un-subscription service Unroll.me has said he’s “heartbroken” that users are unhappy to learn that the company was selling their data, but people are not impressed with his non-apology.

Unroll.me allows users to unsubscribe in bulk from online mailing lists and newsletters - an attractive free service for those with clogged inboxes. There is a catch, however.

The service requires access to users’ email accounts so they can scan for subscription links which are included at the bottom of most newsletters.

After being acquired by shopping app Slice in 2014, the company began selling data about its users. To make matters worse, it was selling the data back to the very same companies users were unsubscribing from, the Guardian reports.

We can, and will, do better. A statement from our CEO: https://t.co/hra3e3ToVx — Unroll.Me (@Unrollme) April 23, 2017

This only came to light as part of a New York Times report about ride-hailing company Uber, which revealed it was buying data from Slice Intelligence.

Slice used Unroll.me to collect email receipts from Uber’s rival company Lyft, and sold the data to Uber, allowing the company to analyze its rival’s business.

Unroll.me CEO Jojo Hedaya wrote a company blog post addressing the scandal on Sunday.

“It was heartbreaking to see that some of our users were upset to learn about how we monetize our free service,” he said. “And while we try our best to be open about our business model, recent customer feedback tells me we weren’t explicit enough.”

“Sure we have a Terms of Service Agreement and a plain-English Privacy Policy that our users agree they have read and understand before they even sign up,” he continued. “But the reality is most of us - myself included - don't take the time to thoroughly review them.“

Hedaya went on to say the company would be clearer in the future, and would continue “protecting your privacy and security above all else.”