Bad service reaction in case of server communication problems

I bought a ticket but the last stage of server contact was hanging, although I had a stable wifi connection. I never got any info whether the ticket was bought or not, the app always showed "no tickets". So I bought the (needed) ticket via the web. Later I discovered that my credit card was charged for the ticket from the app, but still no sign in the app itself nor any email etc. So I had payed the ticket twice.
The support staff was helpful and refunded but kept 10CHF saying that they made me a favor...
Unacceptable in my opinion, since the product was not delivered. A second request for full refund was denied.
I deleted the app and will try to get my money back!

Schlenk4 about SBB Mobile, v4.1