I found a laundrette in Studentski Grad (the Student Town) south of the centre, on ul Prof Ivan Stranski.
Open every day until 8pm, they wash dry and fold, but don't iron. Very good service.
There is one in town, address below.
ul Pirotska 120 (near corner of bl.Todor Aleksandrov and ul DimitriPetkov
open 8-19.00
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