They called me few times on my mobile asking me to pay the debt or they will send the debt collectors to my place . I luckily found the landlord of that property . He sent me a signed letter clearly writing my stay period in that property . I sent that letter to Buchanan after their next call of harrasment .

Based on the preceding passage, answer the following question Why might I have been contacted by agency ?
They thought I had failed to pay my bills .