Am I just being stingy.

This is quite a long post with grammatical errors so if your not bothered you don't need to read it😀.
So the other morning I was late leaving for work and I forgot my wallet, thankfully I found 10 euro in the car for lunch and petrol if I got caught out on the way home. I started to get a bit tired around one o'clock and one of the lads was heading to the shop so I gave him my money for a red bull , I gave him ten euro because it's what I had on me and I waited for him to come back and he did quite quickly , he hands me my red bull and says I have 2 euro change for you I'll give it to you later, I asked him where he went that my red bull cost 8 euro and he said it didn't but two of the other lads said they owe me a coffee. I am not a mean person and I will often buy lads a coffee or even 20 smokes If they are stuck , and they will always pay me back but they always ask and if they are too embarrassed to ask I'll offer. I didn't want to create an atmosphere with the lads so I just said that's fine if I'm really stuck later on they can loan me the fiver for petrol to get myself home, home time came and me and two of the lads that got the coffees where with me in the work van and I asked them nicely if they wouldn't mind maybe throwing me a loan of money until the morning because I hadn't really got enough for their coffee earlier they looked at me like I had two heads. I thought maybe they forgot but then they said sure so and so said he would buy us coffee on him when he went for lunch earlier but he just decided that I should pay for it , now I should say these two lads are the closest thing to friends that I have and they did loan me money to get home but my problem isn't with them it's the other chap that went to the shop am I right to be annoyed that he splashed my cash to big himself up or will I just drop it ? I should also mention I never got the 2 euro change either.