www.linuxiso.org is the first place to look.
You say you purchased Redhat 9? Was this the official boxed set or a CD set from a CD reseller?If you bought the boxed set,take it back and exchange it for another.You may have just unluckily gotten a badly stamped CD.If you got the CDs from a CD reseller contact them about what can be done.
If you decide to download the 3 ISO files(1 ISO per CD)be sure to get the md5sums with them to check the integrity of the downloaded ISOs.
HTH
lynch