An annual requirements contract to deliver file cabinets each month was issued. The contract did not say anything about who bears the cost of uncrating and setting up the cabinets in the offices. The supplier has uncrated and set up the cabinets the first four months of the contract. Now, the supplier is refusing to uncrate and set up the cabinets unless he can increase his price. Can I force the supplier to continue to uncrate and set up the cabinets in the offices at the same contract price?