Leaking Indesit WIDL126 due to pump lid?

After having issues with cleaning levels with my indesit widl126 I decided to check the pump. To access the pre-chamber I took the cover panel of and turned the lid to the pump anticlockwise. Some water trickled out as expected but I am unable to pull the lid out. Not only that but I am unable to do it back up again so the machine is now completely unusable. It's not an issue with strength as my fiance can't tighten it either. It just won't budge. Any ideas?