admission to ESF year 4/5

We have applied ESF in 2017 for Year 2 and been in waiting list. We know that there is a long queue in the list. Our area is in the catchment area of Kln Junior school. We are planning to transfer my kid to Year 4 next year or Year 5 later years. My kid's father is a British. Any suggestion to make the process faster please (apart from buying that expensive debenture) It seems the waiting time is UNKNOWN! Many thx!