Reglazing spectacles

Don't go to high st opticians for this! I do this & have had about 8 or 9 done over the years with excellent results.
I look at other people's specs, find some I like & ask where they got them & often you can find them on eBay.
Once I loved some Whistles glasses & got them on eBay & got them reglazed. I love them & bought another pair from eBay in case these broke. I never use any particular reglazing service but whoever I fancy on the internet, I've never been disappointed. I must have saved thousands.
High st opticians don't offer this service as there's more profit in selling the whole thing.

Spec savers will put a new prescription in older frames problem is for me my frames are low cost but my prescription lens is expensive with thinning, coating andreactalite added. So there is no point.

This sounds like your optician is wanting to make money above providing quality eye care at an affordable price.
I wear spectacles constantly so replacing lenses isn’t an option but my optician will put new prescription lenses in one of my previous frames if possible ie there’s no damage to the frame. And actually, the optician normally sends everything away to a specialist laboratory anyway.