Asking for Help in a Store

Customer: Excuse me, can you help me, please?
Shop Assistant: Of course. What do you need?
Customer: I'm looking for a T-shirt. Where can I find them?
Shop Assistant: The T-shirts are on the second floor, in the clothes area. Do you need a specific size or color?
Customer: Yes, I need a medium size. I like blue or green.
Shop Assistant: Okay, let's go to the second floor. I'll show you where they are.
Customer: Thank you. Do you have any T-shirts on sale?
Shop Assistant: Yes, we have a sale this week. All T-shirts are 20% off.
Customer: That's great. Can I try this blue one on?
Shop Assistant: Sure, the changing rooms are over there. Come back if you need a different size.
Customer: Thank you. It's a good size and it looks nice. I'll take it.
Shop Assistant: Do you want to pay by card or cash?
Customer: I'll pay by card. Where do I pay?
Shop Assistant: Please come with me. The till is just here.
Customer: Thank you for your help. You are very kind.
Shop Assistant: You're welcome. Have a nice day.
Customer: You too. Goodbye.