Spice Jet Airlines — is this a fake offer letter??

Hi this is shruthi i got an email through timesjob for air ticketing and accepted that offer and there was 2 rounds of interview 1st was aptitude test and hr round. After that they told me to pay 5500/- for getting the offer letter and that would be refunded. After few days 7500/- and the 10500/- i have paid all the money to them and now they r not picking my call. Please help me with this.