I bought two travel cards (each for 30 trips - by metro, and by bus, trolleybus, tram). Not only was one amount punched (and then with an error), but a completely different amount was announced. The cashier is rude, as soon as such people are hired to work with people!!!
I've never had any problems, I've replenished my travel card many times. The only time I couldn't replenish it was because the travel card stopped working, I had to replace it with a new one.