Yesterday I lost the plot

I got a phone call stating that the parts had been authorised for my BMW and that they would be ordered as soon as possible. WHAT PARTS? Day 90 and they are still working out what they need to put it back together. All this on top of the fact that last week the story was "nearly finished, should be with you on Wednesday". So when I got that call on Thursday I'm afraid I lost the plot, a little. I called the lease company and demanded to speak to the head of the relationship between IBM and Leaseplan. Then I ask her what on earth they are doing. She was very empathetic with my situation and asked me to email her, which I did.

AND

Today I got a call giving me an update as to what she has done and what she is waiting for and what I should expect to happen next.

Why has is taken them 90 days and me ranting to produce reasonable customer service? I guess I'll never know, but it's very frustrating.