Refusing to replace rusted gate

I had a gate installed through them 2 years ago, last year it was replaced because it started rusting. The new gate has now started doing the exact same thing but getting it replaced is becoming a nightmare. I was told it would take 7-10 days for it to be replaced its been more than three weeks and they telling me it will take another week or so because they dont have paint for it but when i asked if i ordered a new gate would it take over a month and they say no it will only take 7 days because it is new. Why is new and replacements two different things, I was first told my gate is ready but they cannot find it and now i am being told they dont have paint, so which is it?? I have never before experience such bad service, I just got a call from someone claiming to be a technical manager and all he was interested in doing was telling me about the technical part which i dont care about all i want is my replacement product or a refund. When asked to speak to a branch manager I am always told he is not available. All i want is to know when this product will be installed!!!