Hathway — Billing related

Dear Team,

I got a call from Hathway customer service people they told me offer is going on in Hathway Broadband just for 471 I paid 1580 rupees as advance payment and from second month I can do recharge for 471 but now when I am going to recharge they are saying you need to do recharge for 600 rupees they are refusing and doing like harassment kindly looking to this and do the needful