If they just gave you update to a specific container you will not be able to run listContainers. Instead you would need to run listBlobs. There is a very similar thread where a user faced this issue. Please check to see if it resolved your problem.
Hope this helps. If you are still facing issue please share the SAS URL minus the signature and any personal information for us to review.
-------------------------------
Please don’t forget to "Accept the answer" and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.