Do not try to 'push it through' it may get stuck and make matters worse.
Stick your hand down the pan round the bend and try to get hold of it and pull it out. I have to fish things out of the loo often as my grand-kids think it is a great game to drop things down the loo and get Granddad to get them out.
My HB has been mucking about with a coat hanger with no joy. He's furious with me. He thinks we'll have to get a plumber to take off the toilet to find it.
It will dissolve eventually, Sam. For a quicker fix ... the pan will have to be taken out.
I can guess where it's stuck. You may have to "reverse" rod it. That is... from the spigot "sticky-out bit that connects to the soil pipe....... backwards to the bowl.
Knowing the size of soil pipes I find it strange a thin toilet block, with or without plastic, is likely to be the cause. Not tried to flush loads of paper at once have you ?
We eventually had to call in a drain cleaning specialist who says that those type of toilet cleaners were the best thing ever invented - for his business that is! He has more callouts that can be attributed to 'those bits of plastic' than anything else, so be prepared for the worst case scenario....
Having been asked to remove all kinds of blockages from toilets I can only agree with him.
If you are the sort of person who has have blue water in their loo. Fit the decanter in your cistern not hanging over the side of the pan.
I think that the problem is that the plastic holder will not dissolve.
It gets stuck in the pipes somewhere then traps paper etc so blocking the pipe.
If you can get hold of it, do try to retrieve it.
Otherwise, it will be a plumber or the Drain Doctor type of service that you will need.
Good tip by alavahalf....hang the thing in the cistern then it cannot get into the pipework.