I’ve seen this same scenario play out with other customers over the years. I’ve never used GBP but it seems they have a problem with customer service and run out of patience quickly. Keeping the general public happy is not an easy task and requires a certain personality to do it well.
Agreed. When we are talking in terms of over a decade now I'm sure businesses and people can, and sometimes do, change.
However, I've seen cycles of issues from others, have first hand knowledge of 'ownership issues/clouds' on the original parts cars that got the business going when it was only used parts, and have heard from former suppliers/business associates who worked with them years ago about many issues in the organization such as zoning/permitting, substance use by employees. Staffing issues in general, etc.
I will say this... not everyone is cut out to run or own a business on their own, and often there is a need to put in positions of authority others who can supplement your weaknesses. Depending how well you do that, and how good your choices of how and to whom you delegate things are, makes a world of difference.