E-ticket? No change possible unless you didn't download it. In the latter case you can contact the customer service.

Unused tickets from a ticket machine you can get refunded at any ticket office.

Date cannot be changed-time does not matter here in NL, as there is never no REServation. Except for some special tickets (which also require special conditions that incidental travellers will not have) that are only valid off-peak.

THis is for INland tickets-but you did not specify if it was perhaps for inetrnational

Hello, good morning 

I bought a ticket from Amsterdam zuid to Tilburg yesterday (19/02) to use today (20/02) but I bought for the wrong day (19/02). 
 

can I get a refund? I had to pay another one this morning 

thank you, 

Renata 

No, there will be no refund. You may have traveled with it, it is impossible to check this. When fraudulent use is possible, there will be no refund nor compensation.