Refund

Turbo taxed said I would be getting back over 6k do to my 1095A all the info I entered was correct. However I got a letter from the IRS saying I owed them a sizeable amount. Instead of getting any refund I apparently owe 7000 dollars. How could turbo tax make such a huge mistake. All the figures I entered matched the numbers on the 1095A i am so confused & have no idea how I can afford such a large payment