Paul-Grey-Unicorn-386063522 Bunq has no web portal because that is much more prone to attacks, so it makes bunq less safe.
A hot line would need staff, which costs a lot and would cost the customer an international call.
What are the odds that someone loses their phone and their cards at the same time and knows your PIN and there is no other phone around to use the workaround as suggested?
You are being over secure, I think the option bunq offers is sufficient for the rare cases where someone gets in the disaster scenario you describe.
A hotline or web portal would cost extra and I don't want to bare the extra costs for such measures as a customer of bunq. I keep my phone and cards separated, it's just common sense.