bad service

I have got a pair of black wage heels as a gift, because it was a gift i don't have a receipt but the shoes do have a price sticker and the bar code on. i have been to 3 jet stores wasting my petrol trying to exchange the pair for something else cause the are a small size for me but they tell me they can't change cause they are not on the system of which i fail to understand why is it my problem that they are not on the system.

I do understand retailer has no legal obligation to give me my money back as i don't have the receipt but according to the Consumer Rights Act i hold a right of return, repair or replacement if the item is faulty, doesn't meet my expected standard or doesn't fit. Would you kindly attend to this issue because i'm tired of dealing with your rude staff members.

Regards Noxy