Taxes which were supposed to be paid under Service tax were paid under Gst

If any taxable service which belonged to F.Y 2017-18 under service tax act, tax on the same were not paid and same taxes are paid under GST act in next financial year in F.Y 2018-19 by raising invoice.
What can be done in this case to avoid the claim under service tax as such services were supplied in 2017-18.