Hi Melisand, have there been any recent changes in your household, somebody moving out/in, changes in income like an inheritance?
The only way to check your benefit allowances is to phone the DWP to ask why your money has changed.
You could check with your council or with council tax, best to check with the DWP first.
Good luck
Greekqueen
Nothing on this board constitutes legal advice - always consult a professional about specific problems