I've only broken three bass strings in my life. First was a LaBella, years ago. That string was definitely defective and they also replaced it quickly.
Same with DR, had a bad core on a Black Beauty .130 and they sent a new one right away.
Broke another string on my new Warwick, which was my fault really, but the bass had a bad tuner. The Warwick distributor had me trying different things to try to fix the brand new bad tuner and in between trying to explain to him what kind of tuner it was and what the problem was I went the wrong way and snapped the string. He finally agreed the tuner was indeed bad and I mentioned that I broke my strings trying to convince him what I already knew, hoping he'd pack in a new set of Warwick strings with my tuner replacement. No dice.
So what's the point of all that? I don't know. Just wanted to share

I guess I feel like this:
I spent $30 on a set of DR's and one was bad. They did everything possible to fix it.
I bought a new $2900 Warwick (didn't pay that but they don't need to know that!) that arrived with a bad part. They did replace the part (well they sent the wrong color but they tried at least), but it took a few weeks, and I know I shouldn't expect freebies..but you know...$2900 bass...inconvenience...took a while....they probably have about $4 invested in a pack of strings...why not help a customer out? I never would have broken that string had the tuner not been broken.
Good customer service goes a long way.