Very bad customer experience from Cell C Fibre

Good morning Cell C. This is my problem. I have an internet connection, all the lights that need to be green are green. The problem is, SOME of my devices and apps connect to the internet, others don't. For example, while YouTube on my PC works fine, YouTube on my iPad and iPhone says I am disconnected from the internet. While some of my LAN devices are fine (like my PCs) others like my Phillips Hue Hub and Raspberri Pi's cannot connect. At the same time, my work laptop cannot connect to VPN and this is where the call centre get fixated on. They blame my work for not allowing VPN and seem to not be able to make the connection between all the other problems I'm suddenly experiencing and this one. I believe that whatever is causing some of my devices to not connect is also causing my work PC to not be able to connect. I eventually demanded someone to come and see for themselves because the call centre doesn't take me seriously, because they see I do have a connection. I have to pay for someone coming out, but at least I can show that person what is happening. I would appreciate someone coming out as soon as possible. Thank you.

I would like someone to please reset my router and if the problem persists replace it, as the router is the only problem I can think of that may be the issue here. That or the DNS server settings.

Out of desperation, I phoned the call centre again. Although the agent could really have been friendlier, she did assist me in resetting my router and now everything is back to normal. Thank you very much.