Buckle mules for men

I bought my husband a pair of buckle mules in August with the intention of giving it to him for Christmas because he loves woolies mules. I gifted it to him on Christmas day and 3 weeks later we went away on holiday for our anniversary and I noticed his foot looking funny in the one mule. There's a crack right through the middle that cannot be repaired. Woolies I'd like a new pair of a refund please. What happened to quality? For a pair of mules to last for 3 weeks is not acceptable at all. It was a online purchase as well so I could not take it in store. Order number - O***