Cracked bath

We bought a bath tub at builders 5 years ago. Last year the bath got some cracks in. We went into the store in Witbank where we bought is to complain. They gave the reps contact no to us, because he must handle it. We phoned and forwarded Photos to him, he never came back to us, months have past and no one wants to help us! I again phoned builders in Witbank and spoke to a manager and he informed us that there is no gaurantee on bath tubs. How can a bath only last 5 years? the bath looks ugly in my bathroom and since it is a corner bath it will cost us to brake out all the tiles around the bath to take it out.