Make a note in your online journal and ask for your claim to be looked at. If you don't get a response keep messaging them or call them- UC calls are free now
On a basic level you should be getting various elements which make up your universal credit:
Standard element - currently £317.82 (assuming single person over 25)
Housing element (amount depends on if your social sector or private sector)
Child element (dependent on no of children, and if any more born after April 2017 then only payable for two)
Limited capability to Work element
(if deemed unfit for work)
You can be awarded various other elements too, eg: if you're a carer for someone or have a disabled child or have child care costs
If they have reduced your uc because they think you're getting carers allowance you must ask them to check their systems, to prove you've not had it for years.
you appear to be getting very little so could there be any other reason?
Have they made deductions for any advances you've had from UC, or
any overpayments you're paying back from UC or
if only recently come to UC, any overlapping housing benefit (that was previously paid via the council) or
any from tax credits or other benefits eg: jsa or income support?
Are they paying your housing directly to the landlord which would reduce the amount you get in your hand as it were
Take a look at your online statement and see what's been awarded and what's been deducted because the amount you say you received is very low. You can pm me if you like (have benefits background inc several years with UC)