************ and unfair business dealings by an investment company

I invested a lump in April this year with this investment company for them to trade on my behalf. I have also been paying in monthly instalments via Luno since May until October. On Friday the 7th of November they sent me an email to the effect that the trade period has come to an end and that it was time for me to withdraw my profits which are now in excess of a million Rand ( $98,777.077), but that in order for me to effect the withdrawal I have to pay $4580 (which is approximately R73 280) for the withdrawal fee and pin, upfront within 14 days. I find this to be an ************ and unfair business dealing as this was never communicated to me even on my investment agreement with them. Also I do not understand why the this amount can't be deducted from my profits. I therefore suspect that this is a tactic to swindle me out of my investment and profits. What is more concerning about this is that I introduced two other people to this investment company and these people now think that I have ****med them as they are now unable to withdraw because of this exorbitant amount that they are now told is a condition for them to access their money.