Montblanc Montreal review for Shippo ‑ Simplified Shipping

The app is setting some of our products to a negative inventory. We opened a support ticket on March 5th 2021, we got a reply 10 days after from Ralph Aberin apologizing for the delay, and they are working on the case. 11 days after that (today), we got the exact same reply from Ralph. So, after almost an entire month we received zero support. We are now looking for a new (working) solution with a good customer support.