Is my CAS Still validate?

Asking for a friend.

Dear Sir/Madam,

I am writing to ask if my CAS is still validated after my university has changed my offer.

The situation was that I have been given an offer and its corresponding CAS in July. However, last Friday, I received a different offer that changed my admission date to 2018. It has been confirmed by my department that the 2018 offer was another wrong offer, and the Research Student Assistant replied me that she had told the admission office to revert my offer back to this year. However, since I have made a Visa application appointment based on the previous 2017 offer and its corresponding CAS, I am worried that the 2018 offer has affected the validity of the previous 2017 offer and CAS. Now they have given me a correct with a correct course date, which is still the same and from the same university on the CAS.

Therefore, I would like to ask that if a CAS is combined with a specific offer or is it bound to a specific candidate? And is this CAS still validate for me to apply for my tier 4 visa? I have booked a visa appointment but I haven't submitted my materials yet.

I have also called the UKVI immigration for general enquiry, and the advisor told me that I do not have to worry about this CAS and it is still validated as long as it is from the same university with the same course name and course date.

So, is it necessary for me to get a new CAS from the University or I can just apply with this CAS?
Many thanks!

Your CAS is valid for 6 months from the date of issue. Just make sure that your 2017 offer details match the details given on the CAS. Things to look out for in the CAS -
Course details
Start date
End date
Fee details
As long as all the details are correct - you should be fine. Good luck!