Severe and unprofessional customer service

I laybuyed Nike shoes , 6.5 size thinking that I'm not gonna strain my feet and the cuts size of Nike brands are big.after I paid my laybuy I decided to bring back the shoes and get the bigger size which size 7 .5 unfortunately they didn't have the size and they referred me to Westgate branch where i a got a severe bad service at around 15 :15 pm. The sales person where not helpful of me getting a shoe that is around 799 in value and most of the shoes that I choose they did not have size 7 and asked them to check for me with other brands but the salesman cutted me off by saying they don't have size 7 of all the shoes that i was choosing they don't keep size 7. According to the salesman behaivour and facial expression wanted to see me leaving the store as it was around 10 minutes for the store to be closed and he was playing with a step ladder and the other sales ladies were roaming around. I couldn't ask other questions because I know the answer that I will get will be an irrational and unprofessional answer also I did not ask for a manager cause the situation and the surrounding of the behaviour of the employees in that Westgate store branch wouldn't all me to identify the manager or better sales assistant and they did not have their name badge on them so I Don't t know their names.

All I want is size 7 or a nice shoe that is around the value of the shoe that I laybuyed or I would like to get a refund and go to Nike or Addidas store.

Regards Lerato ********** 408 / ********** 442