Synchrony Bank Credit Card Complaint

Synchrony Bank Credit card department,

Billing disputes New York

I am a consumer who applied for a cared credit card for vision purposes in - 2014. I was under the impression that I would not pay any sort of interest for 18 months on my - purchase and would only acquire interest charges after the 18months was over. I received inadequate explanation of the terms from the store rep and at not time spoke to an actual Care Credit rep during the application process. I also did not receive any copies of the care credit agreement that explained the deferred interest rate of the crazy 26.99 % When I went to make a payment online I noticed and interest charge for over $700.00. I called care credit and pretty much told me there is nothing that they can do, but only offered to remove charges if I paid my remaining balance within a week. which I cant. Also only said that they are sorry that the vision rep did not explain how the deferred interest charges would work. I am truly stressed out about these charges and would like your help. I wrote a letter to the corporate office, but was told but a care credit rep that it may take over a month for them to reply to me. Please Help! Thanks.