Disappointed

I was very excited to see an app where I could use a spreadsheet on my iPhone. However I noticed a couple of things that dissatified me, hence me looking for an alternative. First, I would have liked the sheet to be able to use the "split" function given that the screen is quite small. This is not essential but would be very useful. The main reason I will not be using this app is because it does not support XLSX files. I am a mac user and this would be very helpful, but I even tried saving the file as an XLS before importing it and still it did not work. It said that an error occurred in saving the file and it could not be opened. I have no choice but to look for an alternative. Wish I would have known this before it was purchased today. Any way I can get my money back?

Alpine A about Mariner Calc Spreadsheet for iPhone