lack of communication

my loan was handed over to Van Der Walt collections and then later handed over to NRB solutions without any form of communication with me. To my suprice, Van Der Walt is still billing me and NRB as well is calling me for payment. Finchoice never communicated this change and how come am i required to pay R20000 for just a R6000 loan....why 2 different debt collectors? I'm taken for a ride here, such poor service. I want clarity NOW