Special Dividend on sale of 50% of business

[Ceebeeby]

I own tech stock for a company I used to work for. Last year they sold their Enterprise business (50% of total business). The stock price then effectively halved (and with it my portfolio value halved). The company paid a special dividend which equated to the monies made through the sale of the Enterprise business, paid to shareholders on a $x per share held. They positioned this initially as a 'cost of sale' that was non-taxable. But when it was paid out it was declared a 'special dividend which I am told is subject to dividend tax. My question relates to the fact that my portfolio value recouped the 50% drop associated with the 50% sale through the dividend but I'm now being told by my accountant that I need to pay tax on the special dividend. Essentially I'm paying 30+% tax on money that brought my investment (remaining share value & dividend) back to the value my shares were. If I had chosen to sell 50% it would have been subject to CGT but through this process I'm paying tax on monies that were originally mine (in share value). I made no gain through that process (although subsequently the other 50% of the business i still own has seen some growth on shares and of course I'll owe any CGT on those when I sell).

Is it correct that I should pay the dividend tax on monies that effectively gave me back what I already had (in value)? If they had simply replaced share x (Enterprise business sold) with share y (same value in shares in new company) i wouldnt be due to pay tax. So effectively, as I see it I'm paying tax on my own money, where there was no gain.

I obviously want to pay whats due, but i don't understand how this works. Would really appreciate your insight on this.

Many thanks
Cb