Just fill it up


I want to share a little frustration that I recently rediscovered and it goes something like this.

I pull up to the gas station to find out that the outside credit card machine is not working. I go inside to pay, I get this nostalgic feeling of having to change the TV without a remote.

Here is the gist of conversation

Me: I would like to fill it up.
Clerk: How much?
Me: All the way.
Clerk: How much is that?
Me: I have no clue, I just want to fill up the tank.
Clerk: How much do you normally pay?
Me: What does that matter, I just want to fill up my tank.
Clerk: So how much do you want to put in?
Me: OK, how about $2,000 just to make sure it's filled up.
Clerk: (They look at me as if I am some kind of smart ass.)
Me: Fine just put $20 in it.

I normally don't like to post problems when I don't have a solution, but I am afraid I don't understand how gas station payment systems work. There has to be a better solution.