I admire your determination, Bert, but I wouldn't count on it. I suspect the contract in legal terms does not commit them to deliver it. Moreover you are likely to be handed back and forth because there are two contracts: your contract with Bigcompany and BigCompany with BigDelivery so your first hour or two will be getting the right company to take any sort of responsibility.

In terms of the contract itself you may also be on weaker grounds than you expect. I once spent about an hour reading through all the rail ticket terms and conditions back in around 1980. At time Britsh Rail selling you a ticket between two places not only didn't commit them to getting you between those places; it also didn't commit them to ever having run a train between those places, however indirectly.