Toyota Extended service plan - 40% was underwriting fees

I recently purchased an extended service plan from Toyota - Ballito. It cost me R5,600 for a 40,000km and R50,000. I paid in advance the full amount at the dealership and received a receipt. Thereafter they told me the plan will be loaded in 3 days by Innovation. I took the car for the 40,000km service and the invoice total was R2,500 which was covered by my plan. I then took the car for the 50,000km service and the invoice total was R850. In essence I would have been in a better position paying cash for the extended service plans. I have been charged approx R2,000 extra for taking out a service plan in advance. Toyota Ballito and Invoation can no provide me an answer in writing as to the reason for the large variance. A call centre agent of Innovation verbally explained that this is the underwriting fees. R2,000 is close to 40% of the deal. Surely this is NOT the Toyota way!