Rude manager, who was not helpful

I went to Totalsport Germiston to exchange a pair of shoes I got as a gift which was a wrong size, the didn’t have the one I want I chose something else and told them I will pay the difference however he refused I mean I didn’t ask him to refund I just wanted the right size, I honestly never expected such service from a Manager(Thabo) and worse part he gave me customer service number and just left me there went back to eating. Thank to Owen who interven and try to give me a better shopping experience.