I've only ever seen MSDS for individual cells from the cell manufacturer. I cant say I've seen one at the pack level. I would have thought if you know the cells in the pack you can obtain the MSDS for them from the cell manufacturer. Its been a long time since I've bought a pack - I've built my own since then and hence shipping individual cells rather than packs.
Either way, the MSDS sheet for the cells provided to the freight company might be an option to at least get what you paid for?
I have used in the past, and would use in the future, em3ev for packs. I didn't appreciate the quality of their work when I purchased a pack back in the day. But having since disassembled a few different packs and have built my own, and have opened up the one I purchased from them - I appreciate their work and the attention to safety in pack construction ten fold. Further, when I had issues with a charge socket it was sorted without fuss or mucking about and my questions were answered reasonably etc.
I find the different approaches taken by different businesses in the same industry interesting. These days I see a problem/product issue etc as an opportunity to thrive rather than a downer/failure - if the supplier takes it seriously and makes good, they have just obtained a long term customer with repeated purchases!