Practice the dialogue at home:
Shop assistant (SA): Hello! Can I help you?
Costumer (C): Yes, please. Can I have a...?/Have you got...?
SA: No, sorry/Yes.
C: How much is it?
SA: It's ... pounds/euros.
C: Here you are.
SA: Thank you. Bye!
* You can hear and practice pronunciation by clicking on this link. Here, you will be able to write the test you want to listen, adjust the voice, speed and the accent and hear the correct pronunciation.