Product Code 20 relates to the CA Vision Sixty product. Normally the message "Receiving message "CAS9013A Product 2O about to expire or is expired and is in use" is used to advise you that you need a new LMP key to utilize CA Vision:60.
If you are not using CA Vision Sixty then there are only two ways you can receive this message:
1) PGM=DYL260 on the EXEC statement as you probably do now
2) PGM=DYL280 on the EXEC statement
Code OPTION 260 as the first statement in the CA VISION:Sixty program.
We recommend that if this is a random occurrence you may have a program that is submitted with the OPTION 260 specified. Please remove this and it should resolve the CAS9013A messages.