Cannot delete a Google Calendar task now that my Pro Trial has ended

I tried the google calendar task import while on the first 30 day Pro Trial and it worked good, now that is has ended there were some recurrent tasks that I no longer execute and cannot delete them. They always show up because of the rolling over of tasks (which is good but not for this particular setting).

Also, today some that were Google tasks that were executed/finished a month ago show up today (12/07), it's really odd since I cannot edit them.

Kindly advise