It depends - They prepared your return correctly - you can file your 2017 return as a nonresident alien because you only became a H1B in Oct of 2017 and you would be able to claim the treaty exemption.
The days that you were an F-1 visa holder do not count towards the substantial presence test, Therefore only the days that you are on the H1B visa count. So if you switched to H1B in Oct, you will not meet the substantial presence test because Oct to the end of the year is less than 183 days in 2017.
However, if you want to make the first year choice, then you will need to wait to file your 2017 taxes until you meet the substantial presence test in 2018 (so you would need to file an extension for filing your 2017 US income tax return until Oct 15th). You would need to let them know that you want to make the first year choice. In this case, you would file as a dual-status resident. I am not sure that Sprintax prepares dual-status returns.
Refer to the First Year Choice area,
under Dual-Status Aliens, of Chapter 1 in Publication 519,
U.S. Tax Guide for Aliens.
See this link for
additional information US Tax
Guide for Aliens.
