Dissapointed

Im very dissapointed in the service received.. i bought 2 pairs of shoes on the 05 October at 11:18. I paid with my card and when i got home i noticed that the sizes is not right and went back 2 the bellville PEP stores but than they were closed on the 6 October.. i went today and was advised they cannot help me cause i dont have a recepit which i understand.. i told them i dont want a refund just a bigger size, i ask them 2 get a copy of my receipt cause i still have the SMS of the purchase that went off but was advises they cannot get me the copy of receipt either which i fail 2 understand why, as i have the right to the copy as a customer at any given time.. i spoke to the manager who advise she cannot change the shoes and need to speak to her boss that is in a meeting..if the shoes is not change, i have no choice but report this to the retail ombudsman cause the prices is still on the shoes, the only thing i dont have is the receipt which they can get on their system