Oh I wish I had hoped in earlier today, this was a good read.
National12 - If Rob here states that L3M pays their bills, they do. I feel that you should deliver the freight in good faith and be happy Mike found you so you can be paid for hauling this load. I hope you find the true owners of the other loads you took from Tesla.
Mike - I have to say you're trying hard to do the right thing here by trying to find the actual carrier hauling your load. In my experience when contacting a carrier that was rebrokered a load, they were always extremely happy to hear from me, work with me and we all got the job done. The fact that there is any hesitation to deliver and be paid directly by you means I have to suggest whenever the load does deliver, you'd better have the receiver write the name that's on the side of the truck on the BOL and have the driver and he/she sign next to that. In case you need that information in the future.
If both National12 and L3M are telling the truth here, this story has a simple happy ending, deliver the freight and get paid (upon delivery would be nice, but within 30 days are standard terms). Because this is not happening I feel there may be details we don't know about.
Keep well and good luck,
Mike