The popular saying at SFI is 'never give up' however we have also been clearly told that if we are able to retain 3 out of 10 affiliates, we are doing well. There is no need to lose sleep over a CSA that refuses to respond after repeated prompting. What I do is to reduce my number of contacts with such affiliates, hoping that something might change in their situation which will cause them to respond favourably. So ultimately, it is up to you and how far you want to go