A problem with access to none free unit even after purchasing – English Grammar in Use: Sample Review

I bought this app; however after app was updated, I still did not have full access. Every time I tried to read other units, it showed ”the unit is still updating, please try again shortly”, while I have updated app several times after I pay for it. Finally, I purchased the full version of this app and paid again.
Review by Meysam89 on English Grammar in Use: Sample.