AITA for pushing back on a pharmacy charge that I’m sure I already paid?

Had a bit of a dispute with the counter staff at the pharmacy I’ve been visiting for a couple of years now.

When I went to pay for some medication they told me I owed them $7.70 for medication I came in and purchased last week and would I like to pay for it now.

I said hang on that can’t be right because I remember you giving it to me in a bag and he said sometimes the eftpos machine declines.

But i remember paying because i was really nervous about whether or not the payment would go through.

But i paid it anyway because i realised I couldn’t prove it because i paid on a gift card.

Then I remembered i collected two medications at the same time so i said well how come your only charging me for one of the medications but I actually collected two medications that day…..

He said let me look on the system.

Then he said no you collected the medications on different days.

So I sort of decided to forget about it and I waked out but just as I left the building I realised I can check when the escripts were dispensed.

So I checked and sure enough they were dispensed on the same day so I went back in and showed them and they said ok I’ll check the system.

Then the staff member said ok I’ll give you a refund because it’s just not worth it.

And I said well that’s not the point the point is I already paid for it and he said oh no I meant it’s not worth looking through the system because it’s too hard.

Went in today to collect some medication they owed me and ask them to transfer any scripts to a new pharmacy if necessary and the pharmacist was great as always.

But as I was waiting I saw something really interesting on the counter.

A medication box labelled anti \*\*\*\* and I can’t help but wonder if it was put there at my expense!

Anyway…. AITA for pushing back on a charge I’m sure I paid?