Porting failed. Can't receive landline calls

Can someone help me.
My Mum moved from O2 to Lebara in Nov 2025 and ported her existing number but since then nobody has been able to call her from a landline phone, mobile networks are all fine.
We've called Lebara support, tried what they've suggested but keep logging complaints and then trying to call my Mum's phone from landline stating they can't get through ....... I've given them my number to update her but they cannot read or follow a simple request so we are going round in circles. We are now at the point of moving to a new provider but I am worried that if the issue isn't sorted we might be taking the problem with us when we Port again. Any advice welcome.
Rgds Simon

Shandyman64 Did your issue get resolved?

Not a chance, they even stopped following it up as they couldn't get my Mum to answer a phone that doesn't ring. We have moved to another supplier, ported again and my Mum now has the ability to accept calls from landline phones. Lebara 1st line are only interested in logging complaints. 2/3rd line or technical support as they call them can't read and can't follow simple instructions. Hopeless situation.

Not a chance, they even stopped following it up as they couldn't get my Mum to answer a phone that doesn't ring. We have moved to another supplier, ported again and my Mum now has the ability to accept calls from landline phones. Lebara 1st line are only interested in logging complaints. 2/3rd line or technical support as they call them can't read and can't follow simple instructions. Hopeless situation.

Did you get the "it's been escalated, dont worry, it will all be done" treatment?

That's what I got time and again until we got so fed up we left. All sorted in the porting to a new supplier.