TO CANCEL A BOOKING ON A CLUB SITE

I have reluctantly had to cancel my booking for the 2 night week end of 6,7 and 8 July on Tuesday 3 July at 13.20 hours and THIS IS DUE TO ILLNESS. I may be o.k. by Friday but decided not to take the risk of an even later cancellation and let the pitch go to another member. I was not due to arrive on site on Friday until 16.00 hours and with a cancel time almost 75 hours before arrival I trusted I was fair and within the rules but no, my cancel confirmation has resulted in a warning and all for being ill and being responsible in advance. What do we have to do?