We have put together a short survey to capture your feedback in terms of what BT can do when you experience home Wi-Fi issues. We would appreciate it if you could take a couple of minutes to complete a short survey. Read more from here, Fix my home Wi-Fi
My sympathies. BT is not really interested in anything other than easy-to-reach urban & town premises where it can offer high speeds at low capital cost per punter.
If BT was truly interested in nationwide good service there would be regional UK offices with direct numbers you could call where your type of technical fault could be discussed in clear English. Engineers could then be briefed in English to make the (relatively) short journey to your premises and fix the problem. But BT reaching out to its customer base like that is not going to happen.