My main phone is a Doro 6530 and 02 is good around here, for years I was On 02, then swapped to Tesco, again years. The only reason I left is after Covid, they decided my £4.50 a month pay monthly was no longer justified for 150 min, 100 texts, though I usually used 10 minutes and 20 texts max! They wanted me to pay £7.50 a.month, they withdrew my deal! They had actually contacted me about 10 years ago and asked me if I was happy with the contract, I told them no, too much for my usage, so that was how I got the £4.50 deal. I.thought, go payg, so I switched to their service, coincided with dog being ill and other issues...... Phone bill for a couple of months was around £20 a month! I left and went to Lyca is it? Also on O2 at the time......... Then a couple of months later they switched to EE which has poor coverage in the house and around the house! They let me out of contract penalty free as O2, at that time were offering £5 a month pay monthly! I stayed with them just over a year as then they declared ALL contracts going up, alot!
Reluctantly I switched to Lebara due to the cost only, in my Doro, Lebara isn't as good reception as 02, probably because it lives down my bra and my boobs block reception! Down the yard, I have no signal either on Vodafone, probably to do with the steel framed buildings and dips, but EE is fabulous! Just not in the house.
Last year, Sky offered a £1 a month sum pay monthly, I'm now on that until October then I'll be worrying again as to what to do!
Now, I also have a backup dual SIM smartphone, 1 sim is Spusu, £4.50 per month, which is based on EE, perfect for down the yard, sat nav in car, chatting to relatives on WhatsApp etc, the 2nd SIM is Asda (Vodafone) PAYG, that is hardly used and topped up twice a year by £5 a time, I dread them pulling it.
We're in an area where I can put my phone's next to my mum's and barely any signal on them. My dad has a dual SIM dumb Phone, Tesco and EE, even he struggles to get signal some days, yet according to the experts he should have full coverage. He scrapped his landline 20+ years ago due to lack of use. Ours went last year, same reason.
I LIKE Payg, it has its uses, unfortunately when they say you MUST top up monthly it goes against the idea of PAYG, the whole idea was you topped up when you NEEDED not when they wanted you too. My Spusu number was originally a 1p mobile number and I topped up £10 every 4 months as that was the rule. Only reason I left was that rule ended up getting too expensive.
Sorry for waffling, but I really do understand your issue. When I left Lebara, they asked me why, if there were problems. I told them the truth, I have always been On an 02 based network, ever since my 1st phone in the 90's as it works perfectly here for me. But, I also told them that if my deal goes sky high next year, (this year) id probably end up going back to them.