From 
Hello!
Since my concession expires at the end of August, I took a look
a tam som zistil, že TÚ SR má novú adresu: Továrenská č. 7, P. O. Box 18, 810 06 Bratislava 16, a že dňom 1. 7. t. r. sa TÚ SR stáva klientom Štátnej pokladnice a the previously used account in NBS 19-6227-062/0720 is changed to an account in the State Treasury no. 7000136022/8180.
Apparently the postal order type A is no longer valid either, because when I asked for a voucher at the post office they gave me Poštový peňažný poukaz U.
73! OM4DN