The Wonders of Gift Vouchers

Humans in general are wanting to get more for the $$ they pay. So, I'm in that category I supposed.
Kick myself for not checking the free voucher thingy properly. OK.. usually during pre sales I get abit "dizzy" with the free RM vouchers thingy. This time around, the voucher goes like this. Every RM100 of Cosmetics & Fragrances Free RM10 Voucher. Every RM150 storewide spending another RM10. OK... so I spent a freaking RM448 and how much voucher should i get. U do the math.

Sigh! As story goes... I didn't calculate properly or somewhat confused as I used a RM50 gift voucher to get a RM50 off my total purchases and I'm not sure if using that gift voucher my total purchases is RM448 or RM398.
Cut story short. The department store staff.. calculate wrongly and gave me RM10 voucher short. Grrrrr....
One week later.. I went back to check with them at different branches.. I got this answer :- "I'm sorry. You should have come the day u purchase. We can't give u back the RM10 voucher now."
How do I know? I can't be shopping all day.. I'm not as free...Thinking of saving my breath.. all right. Lesson learnt. Always check and double check on the vouchers... Don't trust staff 100%. They make mistakes too!

Blamed myself for being so careless.. I felt duped and the thing is...that's the only department store that sells the cosmetic/skincare that I use.. the irony of it. Sheeshhhhh..