Replacement Tyre under guarantee not supplies

I asked for a replacement tyre in the last quarter of 2014 that was under guarantee and i am still waiting for it now. It is more than 4 months now that i have had no replacement. During all this time i have never had a single phonecall to apologise, explain or give feedback. I always have to contact them and never get any feedback. It is bad enough that it seems impossible to replace my tyre, but it is worse that no one there seems to care about it