Disappointing, misleading competition

I won 3 prizes on the 12th. They called me minutes after winning the 2nd prize to get my bank details. I alerted them to the fact that I was not able to insert my contact details for my 1 st prize as I lost internet connection and when I reconnected it said invalid. The lady asked the time and the amount I won and she took the code and said they will investigate. Before speaking to her I had also send a message on their Facebook page and later got a response congratulating me and that they will be in touch. On the 14th I received the eft for my 2 other prizes. I messaged them again on Facebook To date no response. I want to know why are they running a competition and then decide which prizes they want to allocate. What's that. I find this very misleading, disappointing and unprofessional