Sealing off 110mm Waste, Well is it Really 110mm

[JC1]

Hi All

I'm ripping out my downstairs bathroom to create an office!
Its going well, all ripped out and now I have the simple plumbing task of plugging the what looks like a 110mm waste pipe.
I've cut the waste back to remve old entry points, and from Screwfix bought the Floplast Underground Socket Plug which in the reviews mentions just slides into the waste, so perfect for me!
Well I just cant get the bugger to fit in, its almost the same size as the actual waste pipe, I read some tips and decided to file both pipe and plug to 45° angle, which I've done. but still it doesnt fit...
Driving me insane last night this was

Any tips?

the plug - https://www.screwfix.com/p/floplast-und ... plug/43416

Thanks
JC

[JC1]

Folllowing on from my post, picture now added.

What you think?? I'm a DIY disaster? :)

[trevbul1]

Personally on two previous occasions I have stuffed the pipe with rags and then sealed it with 4" of cement with a little PVA added. Worked fine.

Regards, Trevbul1