Cannot install latest Microsoft Office suite on my MacBook Pro

I am extremely irate.

Bought the latest version of the Microsoft suite for my Mac [Book], only to find out that I cannot install it because my laptop is classed as old. I paid over £1500 for it. Yes, it might be a few years, but I rarely used it and have used up less than half of the memory.

Therefore, I am asking what can I do right now to resolve this situation? I do not want to spend any more £'s on a new laptop.

Presently, I am asking myself, why should I purchase apple products when in a few years it will be obsolete?

[Re-Titled by Moderator]