no feedback regarding my query of keys

I took my car for a service and also informed them of the factory fault regarding the keys .The one key started opening up till it eventually become in pieces and now I'm using the spare key, and hardly two weeks it's also starting to open up like the first one .When I went there they told me that the lady who deals with warranty is currently not available till Friday , so she will give a call that Friday ...I waited but never called .I then called on Monday and was transferred to that who was dealing with my case , she first gave me an attitude and told me that as soon as she has feedback she will let me know and hung up on me.Today I called again and same thing ....she will get back to me as there is no response from the head office ..The key is starting to tear apart badly and it will mean that I won't be able to use my car anymore, such an inconvenience it will be for me .I'm really disappointed with such service , I really don't know which steps I should take now cause this spare key won't survive much longer .