You said you wanted to "pay for my 2017 taxes." Were you trying to pay for a 2017 tax return that you started in Online TurboTax prior to the October shutdown? You can't finish and file a 2017 return online at this point; you have to use desktop software. Or did you pay for 2018 desktop software instead of 2017 desktop software?
In any case, in the answer section below I'll tell you how to contact TurboTax Support.
"I had gotten a few extensions."
I'm not sure what you mean by multiple extensions, unless you had some special circumstance such as disaster area, being out of country, etc.
