no you don't get a corrected w-2 for the excess contribution. you should have received a 1099-R if it was refunded in 2019. if the contribution was in 2019 and the refund was in 2020. you will receive a 1099-R in January 2021 to report on your 2020 return. it will be coded in such a way that it will show up on the wage line.
based on 2019 coding it would be code 8. it will actually appear on the line for wages.