Sony Playstation - PS4 controller issue

I had given my PS* Controller (under warranty) for repair on **th March and I was promised a resolution within a maximum of **-** days.
It's been ** days since and the issue has still not been resolved. I have been made to understand by the Service Centre in **th April that Sony does not have a blue colour in stock. So they asked to take black colour controller as a replacement. It's difficult to believe that blue colour is not available since I see it being sold on Sony Website, as well as being available with other retailers. I had informed the service centre that I do not want a black colour. However, I am ok with the following colours - Red, Silver, Transparent ones, etc.

Its been a week since then and I am being given contradictory information with regards to the status of my complaint. Every time I call the service centre, they tell me they will escalate to the head office and call me back. They never do. In fact, they are not even able to provide me with turn-around time. I had never expected such poor service from a brand like Sony. Please help.