Sounds like what we would term 'a crock of shit'.

Happy that YOU and a pal or two seem to have solved it. Barrel straightening IS part of the manufacturing process, and can be seen a gazillion times on Youtube as the workers, with the barrel on a wheel with handles, pull and twist the barrel in the clamp to make it straight

However, you, the end user, should NOT be able to see a bend in a barrel, let alone one that is as you describe.

My days of buying stuff from FWB are long behind me, but this saga of yours would give me serious concern about spending money in their direction in the future.