HDFC Bank — Not converting purchase amount in emi

Address:

New Delhi, Delhi, 110074

Dear Sir I am useing hdfc cridit cards for 7years.every time when i use this card they simply refuse to convert in monthly emi.whn i contect c care they have only answer cards have no emi offer.so in 7 years i paid them lot of my hard enerend money. this is simply a cheating case.plesase give me right suggestion.