Annoying Company

Hi i have taken a loan with Sanlam/Direct axis-i have been.paying them.everymonth-I was not informed the account was handed over to Norman bissets and Attorneys. Made arrangements with them.payments is done everymonth and i have proof of all payments and statements All.of a sudden i get a call.from.this Sigma Sa cape town which i was not notfied woth the poppy act i dont know how they got my personal details -i must t pay them .Yetthe account is stillwith norman bissets &attorney's. Sigma Sa is a damn annoying company calls u every minute when i sent emails explaining to them.