Mr price theives

After ordering from mr price online i realised the shoe size was incorrect and quickly phoned to change size- lady tells me the parcel had already been shipped i can exchange in store. After 4 days waiting i call and the lady advises me to cancel the order and I will be refunded..... so i agreed and im still waiting for my refund 10 days later im extremely mad as i have now missed my neices birthday gift!! Mr *****ing my money!!!! Give my money back!!!!!