Bad Technical Service

We have been using MTN Business for the past 12 years as an ISP and have always received good service. In recent years, the service has deteriorated drastically. Our problems are referred to executive complaints and it does not help much either. We've been experiencing a data link issue since March 11, 2021, and it's still not available. I would like to escalate the matter further and would like to request the contacts or email addresses of board members or directors.