mike coughed up some electrons that declared:

Thanks for all the advice so far, guys.

I just phoned the BCO. He said that as Anglian are FENSA registered
they can self-certify and essentially tell you any old **** if you
challenge them. However since this is a 12 foot span, 10 courses, 6mm
gap he'll be out within the hour to see if they've created a dangerous
structure.

I'll keep you posted.

Very wise. At least you'll know the extent of the situation soon.

It'll certainly give you some ammunition for no cost, and more importantly,
you'll have an opinion quickly. I agree with other's opinions regarding
rectification. Don't trust Anglian to fix it unless they're being
supervised by someone you trust.

Good luck. Keep us posted.

Cheers

Tim