I was declined an exchange

I bought shoes at Ackerman's Newton junction on the 20th for my son , but they were too small I went there today to exchange and the Manager of the store Daniel gave me bad attitude about how he won't allow me a refund because the shoes were not in good condition, while they were absolutely fine, I hv worked in a retail store before and I know what type of items cn be returned , I received absolutely bad service from him and I was denied an exchange