Consumer Cellular turning me into collection agency for late fees i do not owe Portland OR

i tryed consumer cellular phone  service for about 3 weeks and could not get a signal,  so i cancelled the service, i payed the bill for a month service $21.00 , i never used the service,  i paid so they wouldn't turn me into          collection agency, ever since then they have charged me $5.00 a month for over due bill its now up to $ 25.00      dollars and they are turning me into collection  agency, i think this is unfair since i never used the service,           i will not reconmend  them to any one.   i'm 80 years old i feel like i've been taken advantage of and treated unfair.