Hi ok best tell you all I work for an insurance company sorry.
There are three main types of Gap insurance the one you had finance gap - pays the difference between your Kia's valuation and the outstanding finance/ rentals.
Return to invoice pay's the difference between your Kia's valuation and the invoice price you paid.
Vehicle replacement which will pay the difference between your Kia's valuation and the amount of money you need to spend to buy another Kia the same age, mileage and condition as yours was on the day you drove it away from the dealership. This does not mean that you will get a new car. If you bought a two year old car you would get another two year old car. If you are thinking of this type of cover check out who gets paid. Some insurance companies pay the dealership, some pay you. ( if poss always get a policy that pays you as it puts you back in control of how your money is spent.)
It sounds like in this case you where told about discussed a form of return to invoice but then for some reason ended up getting finance gap. Not sure why? You may want to talk to your dealership about it. They will be able to give you paperwork and copies or everything that you have signed.
Gap insurance is just like any insurance and there will be terms and conditions. Just Google Gap insurance get some quotes and make your own informed choices.