Squealing brakes on Bailey Brindisi

Alko. have had a problem with inferior brake shoe material on some of their chassis and it was as fitted to several makes of caravans , 

I do not understand how your dealer? is not aware of this , which was a no cost to owners rectification , by fitting ,New brake shoes and in some cases new brake drums because of scoring by the inferior shoes

Has this problem been a long term fault or recent ,which may affect if it can be done at no cost to you