I had the same issue previously. i presume they gave you an email stating you have 28 days to put it right?
Then that is what you have to respond and you can equally request additional time if they haven't responded. I studied law so it comes in very helpful with contract
Notices can be scary but they don't have to be.
All you have to do is do the best you can to what you believe to be correct in your understanding of the initial agreement. Screenshot and reply requesting 28 days for their response. If they don't respond, they agree to whatever you've submitted by acquiescence. This can go on for years if you really wanted it to lol.
in all honesty, be polite and honourable in your approach. hope that helps