I need help finding cases to support my argument.

this is my argument, I think I articulated it well enough but I need to find a few cases to verify and hopefully support my claim.

The manufacturing Corp is still eligible for the 10% discount since this was their agreement with Steel Co. that they would provide the manufacturing Corp with the 10% discount, unlike its other customers, since Steel Co. expected the manufacturing Corp. to be buying large quantities of the rolled steel. This was not part of their agreement but rather just an expectation, and now that the manufacturing Corp. has diverted its operations and now uses more plastics and less steel, they tend to buy a small quantity of the rolled steel. Because of this, they are still bound to the 10% discount since their agreement did not specify the quantity of steel they should buy in order to get a guarantee for the discount.

When the Steel company refused to grant Manufacturing Co. the 10% discount, Manufacturing refused to pay anything more than 90% of the amounts Steel claims it is owed. Steel has refused to ship steel to Manufacturing unless Manufacturing pays the 10% difference. This caused the Manufacturing Corp. a loss since their operations requiring rolled steel stopped; hence, they can sue the Steel Co. for breaching the contract and causing them the loss.