British passport renewal refused due to error on South African passport

Hi. My husband applied to have his British passport renewed at the beginning of December. Today we heard that the renewal had been denied as there is an error with the spelling of his middle name on his South African passport (spelt Earlev on his passport rather than Eardley).

This has been a long standing issue with all his documents in South African and all his passports and ID documents have the incorrect spelling on them, which has never been picked up before by anyone along the visa, naturalisation or passport process.

The home office has asked that he either get a new South African passport or a letter from the issuing department to say that it cannot be changed.

Considering that some people have waited 18 months for a new passport through South African house in London and I don't have much faith in them getting it right even after all that, what do people suggest? We're considering renouncing South African citizenship or even changing his name here in the UK to align with his South African passport.

Does anyone have any suggestions?
Thanks

Hello

Is it his first British passport or is he renewing an expired British passport?

It is a renewal. He has had a British passport previously.