They said to me privately that is was a Muslim divorce just like it was Muslim marriage.
Muslim divorce is Verbal. They are allowed to practice those customs in their own regions.
Mynboi, I would base your argument NOT on the fact that you're allowed to have plural marriage. They will not like it. I would base it on the fact that the first marriage was not registered and it was made and dissolved in a traditional or tribal manner.
Yes, whatever you do don't listen to what all the Pakistanis did! Those people obviously tried to trick the system. There's a reason their processing time is so long