how can i fix my toilet,made by TWYFORDS?

i am told i have a double trap toilet with something caught in one of the traps, which is stopping the waste being disposed of in a single flush. the basin also fills with water, and then drains slowly away to arive at its normal level.
question. how do i retrieve the unknown item from the trap. a plunger has not worked and whatever is in the trap has not deterated in the past four days.