Opinion needed - toilet waste pipe

[dandeliondandy]

Hi I live in social housing and just had builders around to replace a cracked toilet bowl. They have done it but when I looked at the back, they have jammed a smaller diameter pipe into the existing waste pipe leaving the interior of the old pipe exposed. It looks awful and like the job hasn't been completed properly - a bodge job in that the toilet flushes but NEVER have I seen a toilet waste pipe left exposed like this except when I was working overseas in very poor countries. I don't think the builders would accept this in their own homes. Can even see the brown staining on the old waste pipe exposed! Please can someone advise and tell me how to correctly describe this to the works scheduler at my housing association? Thank you

Firstly, it will be sealed, even though it doesn't look like it is, but appreciate it doesn't look pretty.

They have left the remains of the old style of pan connector in place and just slipped a new pan connector and seal inside the existing soil pipe.
Would have been better had they cut back the old soil pipe, removing the old pan connector (the larger bit), added a socket and short section of new soil pipe all the way up to the back of the new pan. That way you'd see no old pan connector and not much of any new one.

It's been done like that simply for speed and ease.

Thank you so much for responding. I guess that these contractors will charging full whsck for a not very professional job and left me with the stained interior of the old soil pipe showing. It is never going to look clean even if I bleach it to kingdom come! If I had employed a private plumber I would not have expected them to leave it like that.