Ongoing ping spikes, jitter, and packet loss — technician visits haven't fixed it

For about 1–2 years, my internet connection has had frequent ping spikes, jitter, and packet loss, confirmed through speed tests, bufferbloat testing, and in-game network diagnostics. Despite many support calls, multiple technician visits, and a recent plan upgrade, the issue is still unresolved. I'd like to be connected with a senior technical/escalation team to get this properly looked into. Happy to share account details and screenshots by direct message.