complain on tv licence debt

In 2008 had a bit of cash and wanted 2 buy a tv which was on sale for my grandmother who is unable 2 walk had all his documents with but they said can only buy it in her presence. So i ended up making a tv licence under my name in other to buy the tv. Note that my i was unemployed at that time. Went 2 university for 4 years (so my grandma has tv licence which she's paying for. My father has tv licence and nw i have tv licence 3 licences in one household) i could not pay for mine coz i was unemployed and i was a student for 4 yearz so nw i've been constantly harrased by this agent saying nw im owing R3000 for tv licence. My question is how can u place debt on me during a study period and how can one household pay 3 tv licences. And if ur sytems are working correctly couldnt u see that i had no income for the past 5 years. Im nt will 2 pay for the perriod when i was a student