<prompt> Human: This is being typed on my mobile from work, as I had already left when this issue arose. My wife has contacted the company, not me, and I may be lacking on a few details.15 months ago, we purchased a mattress and used their recommended financing service for no interest for the first 15 months. The credit line was opened with TD Retail Card Services, a part of TD Bank. This morning, my wife noticed the balance had jumped from 400 to 900 approx. We were given no warning and did not realize we were so close to the deadline. After speaking with a cust rep, the money added was the accrued interest during that 15 months. They said the only thing we can do is pay they entire new balance - 22.Is this a common practice? If so, what are some possible ways to lower this?  <response>: Is this a common practice? Yes. If so, what are some possible ways to lower this?Read the terms you agreed to more carefully in the future. 