Broken whatsapp support, incredibly long waiting times on call centers & hanging installation request

Placed a fiber order a half a month ago, got 2 generic emails that they are escalating my email. Attempted the "super fast" whatsapp line, the first time I waited ~5 hours (10:28- 15:09) to be connected to an agent, where my issue had no other feedback than being escalated. The second time I tried an agent I waited 3 hours, again just escalated, the third attempt timed out on COB.

I tried their phone, and I can consistently get to the sales department (of course!), but they can't help me with anything. As soon as I need to get something done I get transferred. I had a 10% success rate at getting to an agent, after an average waiting period of 5 minutes (I generally hang up after 5 min, but I have tried waiting to 20 minutes to no avail). My only verbal feedback was that they were "escalating" the issue.

Being my first interaction with them I thought better I try to cancel this and go with a different ISP. I can't cancel via whatsapp, because I can't reach an agent anymore (waiting times keep expiring due to the 24 hour session limit), I tried to cancel over the phone, but I keep waiting for an agent. I asked if I can cancel over email and the sales rep said I couldn't, at least I can always reference the 8 calls I tried to cancel with a sales rep that are apparently recorded. No idea how I'm going to cancel this.

It has been a nightmare working with their after sales support. I cannot recommend them.