Dual-sub feature failed to display

As of today, I still have not received any response or technical explanation, let alone an apology, for the serious incident in which the dual-sub feature failed to display. This is the core product I came to you for, and the reason I was willing to pay to use it and support your project team.

I had planned to recommend your product to my students and friends, but fortunately I have not done so yet. Otherwise, I would have lost my credibility by endorsing a highly disappointing product.

This will be my final message regarding the quality of your product. If I do not receive a response within the next week, I will cancel the service. Thank you.