Microlighters

I have applied to Botswana Civil Aviation for a permission letter to take my trike up to a family game farm for a week. I trailer up to the Ghanzi area and rig and derig there.
This is the third time I have done this, but they have now told me that I must pay Pula500 to get this permission letter (operators certificate for foreign registered aircraft less than 5700kg).
I questioned them about this and they told me the act was introduced on 30 June 2004 and they have only recently started enforcing it.

Has anyone else had this experience? Is there any other option?

Steve
ZU-ALC

We flew via Pilansberg, Gaberone, Kang to Ghanzi in August 2005 in our STOL CH701 "SkyJeep" and the Botswana DCA applied no such fee at all

This was raised some time ago on Avcom I think. Seems if you drive to the border post and rig it on SA side fly it over the border and derig no fee. If you take it through by car there seems to be a problem (Import permit required?). 3rd hand info, so treat as such. I been up to Francis Town plenty with the C182 via Mmabatho/Pilansberg and there been no fees other than landing and parking.

OT
Flying doctor in Bray area has 2 aeries C210 reg in SA and a Zodiak reg in Bots to avoid all the BS. His farm is on the border, so all Bots "calls" he make with the Zodiak and SA (Usually much further) with the C210. He is a hell of a character.

PS
Also has interesting autopilooooot installed in the Zodiak by Name Philliemon, but that another story..