Hathway Broadband Internet Chennai - Not refunding security deposit amount

I got new connection for my friend on ** Nov **** by paying router deposit amount of Rs ***. Then i got new connection for my home on ** may ****. The first router was returned to them on july **** and the second router was returned on **/**/****. But when i enquire about the refund status they say that customers who use their connection for minimum of * years only will get the refund amount and i was not informed about this terms and condition from then in advance. Also when i returned the second router a lady from hathway called and promised that the second router has refund and the amount will be refunded * week from submission of router. Till now i did not receive refund for any of the router. When i called the lady today (**/**/****) she said that she will check the status and get back to me and when i called the second and third time she did not pick up the call.