Poor quality ink

I bought a printer from the supplier. They sent me a secondhand printer that broke within a week. They supp**** me with another printer with a set of ink cartridges. After about 30 - 50 prints the printing quality became very poor. I sent the cartridges back and they promised me good quality cartridges of which I bought two sets. The quality of the cartridges were just as bad as the previous set. I sent them back and haven't heard from them again. I think it is poor service to sell bad quality goods to a client with a lot of promises.