I cannot increase the font size on an epub?

I have tried to increase font size via the instructions under "Reading" and also via the drop down on the RH side but to no avail.

Contacted adobe chat customer service and apparantly spoke to a real person!!  who advised after waiting quite a while 'Support is no longer available for your product version. Phone and chat support is not available for free or discontinued software or services. You are welcome to visit our Community Support Forum:"

Only downloaded Adobe Digital Editions earlier this month.... although this is free, there should be support