Good business service

***. I received an SMS from SARS reads as follows; Taxpayer ********** 172, SARS would like to remind you to submit the relevant material for case number ********** 61. Please submit the requested information to SARS by the due date on the letter.

Ayanda Ndlangamandla, please assist me. I am not sure of the material and information that SARS want. I also don't have an idea about the letter that SARS refers to and the due date. Please advise on what to do to respond to the SMS from SARS.