Lack of customer care and loyalty

Absence of customer care and loyalty. Bought running shoes at Adidas Moffet Park and was given the wrong ladies' size. Have been trying to exchange this ever since with the excuse of "waiting for head office" to advise if we must accept the exchange. This is after I have spent a considerable sum on running shoes over the past 6 months at Adidas. I'm not asking for a refund but an exchange, as I need alternative running shoes to the ones I have. Can anyone at Adidas "Head Office SA" please make a decision, as you are losing a longstanding and loyal client.