Thanks a million @GSheehy for your very valuable insight which is very much appreciated. The number of employees in the pension isn't known (I have asked the broker and I am still waiting for his reply) but I guess is that it is relatively small.
Steven, even with those charges, are they apply every month? Because it is hard to reconcile the numbers with your assumption.
@ClubMan you're probably right most probably the employer's contribution is only 2.5% in the end which is just unfair on us because if I quit the plan now, I will be hit with more penalties. I wish I was aware of all these hidden costs before signing up.
As I said, once I have spoken to the broker, I will definitely update this thread as my experience can help someone else.
I'd personally check in with company's HR people in parallel, to discover on what is expected by your employer on fees and allocation rates (for both, your and your employers contribs) since you're on their pension scheme and they were setting it up they will know it for sure (or will know someone internally to ask).