Would not exchange a product which did not meet our requirements

I bought a laptop at Esquire for a client of mine. On my way to the client , the client called me asking me if the laptop can be connected to a docking station as that is what the client requires. I then phoned Nikita at Esquire , asking her to check whether the laptop is compatible. She tried to check on her computer or somewhere , spoke to a few colleagues of hers and eventually told me that the only way is to check underneath the laptop to see if it can. I was driving at the time and told her that I will check. I got to the client and opened the laptop to find that it does not have space for a docking station. I immediately phoned her back and said that it cannot and that I would like to please exchange it for a laptop which can handle one. She then said sorry but they cannot exchange it as I opened the laptop. ??? I then said to her that she told me to check underneath the laptop. How can I do that without opening the box. A manager eventually phoned me and listened to the recordings , where he then told me that the sales lady never told me to open the laptop. What a laugh. How can I check without opening the box. Anyway the client does not want the laptop and I now sit with an expensive laptop which I do not need. He just did not care at all about what I explained to him. Protecting his Sales lady was more important than his client. Anyway I have checke the consumer act and I have a very strong case and will take if further with my Attorney. Will never purchase from them again.