Kerovit — Defective pieces

I have purchased two commodes of kerovit during last December and from the very first day the commodes have been clogging. On calling the local customer care multiple times, the guy keep on behaving rudely saying that its not his job to solve the problem, he is there just to register the complain and the plumber keeps on visiting the site after two days when the problem arises. Till the time he arrives there is no physical evidence to show him the issue and he suggests just to put in some acid or chemical... We have been doing it for 3months now and still the problem is still persistent. I am not satisfy with the doings of kerovit and want to replace both of my commodes with proper ones. Whenever we try to contact the customer care he says talk to your dealer, talk to your plumber, make the plumber write a report and the plumber is refusing to do so.