Support with relevant legal provision and cases.

3. (a) in performing a contract of sale of goods, there may be a situation where the seller fails to deliver the goods in the agreed quantity. Discuss the rights of the buyer upon such failure. (10) (b) Mel complains about a shabby t-shirt that was delivered to him by an online trader upon his purchase, but the trader refuses to issue a refund on the ground that the t-shirt is a clearance item. Advise Mel