This is terrible of me to butt in. Jeff can correct me...

"Why Refills table should not have CustId from customer table"

Indeed: On the Refill table, put PrescriptionID in and pull out the CustID.

This way when you link Refills to Prescriptions (via PrescriptionID) you have about anything you would ever want to know, including CustID (becaues it is already in Prescriptions).

"what table should I put pharmacyName and PharmacyPhone"?

Study his link and see what design you come up with. There's many ways to refactor that.

Kurt