Even gifts require the slip

I was recently given a top purchased at Zara by my sister. It had bat wings so I wanted a normal sleeve so I wanted to change it for another top. But because it was in its original beg still with the price tag on this was not good enough I had to produce the slip. I said I don't want money or a voucher I want a different top please can't I swop it - HELL NO. So I had to leave ask my sister if she still had the slip which lucky for me she did and schlep back to the waterfront. I've been able to change stuff for bigger sizes etc at woollies without the slip. But the manager on duty that day was rude. I was going to shop for more stuff but with that bad attitude HELL NO they ain't getting 1 more cent out of me...