A Troubling Conversation

Postal Worker: How would you like to pay for that?
Me: With this credit card.
Postal Worker: I don't see your signature on it. You can't use it.
Me: That's my signature right there (as I point)
Postal Worker: I can't see a signature, you'll have to sign it
Me: Fine, I'll sign it again.
Then, I actually sign it again.
Postal Worker: The signature doesn't match your license.
Thinking "Could it be because it was signed twice?"
Me: Well, you just watched me sign it, you have my ID and know it's me. Can't you just take it?
Postal Worker: No. I can't see your signature.
Me: Wait, before you said it didn't match and now you say you can't even see it?
Postal Worker: Must be the pen.
Me: I used your pen.
Postal Worker: Well, try this one.
She hands me a different pen
Me: Fine.
Then, I actually sign it again.
Postal Worker: The signature doesn't match.
Me: I've now signed it three times. Probably gonna look a little weird there.
Postal Worker: There's no reason to get upset.
Me: If you can't take my card, I'll be a little frustrated.
Postal Worker: I can't
Me: Can I see your supervisor?
Postal Worker: Yes
Supervisor: Sir, your signature is not on this card.
Incidentally, I like it when the supervisor actually asks for my side, even if they ignore me afterward.
Me: Well, I've signed it in front of her twice, what would you like me to do?
Supervisor: I need a signed card
Me: That's my signature, right there.
Supervisor: It doesn't match. The first part does, but the second part looks a little different.
Me: What can I do?
Supervisor: Sometimes it's the card.
She applies tape to "remove" my old signature and allow me to sign anew
I actually sign the card, yet again.
Postal Worker: I still don't think it looks the same
Supervisor: I think we should just take it, there's a line of like ten people now.
Me: Thank you. How come noone else gives me a problem for my signature?
Supervisor: We have a different agreement with the credit card company.
Me: I don't believe that.
Supervisor: Oh yeah, if the credit card company comes here and finds out that a card doesn't actually have a signature on it, they won't pay us. Other companies don't have the same restriction. They get paid no matter what.
As I think, "How would the credit card company know if the card has a signature or not if you don't keep the credit card?"
Me: Can I please have my receipt?
Postal Worker: I can't give you one, until you sign this pad?
Me: Well, I certainly have had practice signing things today.
As I sign their little electronic tablet thing.
Postal Worker: Really, what do you do that requires you to sign things?
Me: I try to buy real estate.
Postal Worker: Can I get you anything?
Me: How about the receipt with the tracking number?
Postal Worker: Oh, I didn't think you wanted it, so I don't have one.
Me: What's that on your printer?
Postal Worker: A receipt...............Oh, here you go.
Me: Have a nice day.