Well it looks as if its already touching the wall above the window - that'd discourage it from growing taller. Otherwise, too dark to see any detail of the plant.

Does it need repotting? Also it looks as though it has been in the same position a long time without turning, which would make it grow leaning over. If it were to grow more pads on top at present I think it would make it top heavy. However try feeding it for now with a very WEAK
soluble NPK fertiliser such as Miracle grow. They can't go on indefinitely in the same compost without feeding.

I have been told it's a grizzly bear variety ....very common and definitely not going to get taller .....it needs repoting and it also needs a new home as I'm moving . Thanks xxx

If that's what it is is will get wider so it needs a wider pot as well as fresh compost. Be careful handling it as all opuntias have little barbed hairs which can embed in your skin. If this should happen remove them with sellotape or sticking plaster, don't attempt to do it manually as they will break off.