Why do so many people here feel it's OK to short change you

Hello All,

I have been to several stores where if they did not have change they feel it's OK to simply not give you anything or even give you an explanation. I can understand this if it's 5 or 10 pesewas, but yesterday I was at an expensive restaurant in the mall and the total bill was 129 cedi and 25 pesewas. I gave them 140 cedis and the person gave me back 10 cedis. I asked him where was the rest of my change and he told me they did not have change. So, I asked him who should be responsible for them not having the change; the customer or the restaurant. I then told him that I believe if they did not have change then they should simply give the customer an extra cedi and not keeping 75 pesewas that belong to the customer. So he asked if he should bring me a cedi to which I replied "yes". I of course left a tip which would greatly exceed the cedi because he offered excellent service, but I am just wondering why do Ghanaians feel that this is proper.

Thx!