Wifi calling - I can't make calls

Is there a quicker way to contact Gigaclear than the contact form on the website, which says "We'll get back to you soon", whatever "soon" means.

I'm dependent on wifi calling when using my mobile, and have no landline. It's generally been OK but more recently I keep missing calls - not always but fairly regularly - and yesterday/today I can't call out at all.

Wifi connection is great, stable, no problem with websites or apps. It's only phone calls.

A Gigaclear tech said it could be micro dropouts as the connection swaps between the main router and the extension upstairs. After years of intermittent internet dropouts, this is the first time anyone's suggested this... but never mind. This isn't internet dropouts when using the internet, but phone calls.

Usually I'm mid-call or mid-ring, when it suddenly cuts off. Exactly if the other person hung up.

I'm very used to having to sit out in the porch where I have mobile signal, to make a call (or be sure of receiving one that I'm expecting), despite wifi being good all over the house. Usually once connected, I can come indoors without losing the call, so that's on wifi since mobile signal doesn't reach everywhere - at least if I placed the call though less reliably if they called me. . Just now, I've tried a few times and even out there it's just as bad.

Obviously I can't call Gigaclear about this either!

I have some fairly urgent calls to make today (officialdom, financial, et al.) and I'm stuck.