If you are in receipt of HB you may apply for Discretionary Housing Payments.They are not payments of housing benefit. There are some circumstances where DHP cannot be paid but I would have to ask you too many personal questions, so
if in doubt, my rule of thumb is always apply. There is no set claim form for a discretionary housing payment . It is up to your local authority to decide whether to accept a claim and in what form. You should find out whether the local authority prefers claims in a specific format. Then make a claim in writing and keep a copy. A claim should include the reasons why you need a discretionary housing payment (severe financial hardship, possible rent arrears-caused eviction etc etc). The local authority may request more information depending on what it thinks is appropriate. There is another thread here about DHP- have a read.
Next, find a welfare rights agency in your area and appeal the "no backdating" decision. This has to be done ASAP, as there is a limited period for appeals. I would advise you very strongly to do this rather then seek advice from here as we may only help in general terms and often don't have enough info etc. You can use
The Directory (don't forget to tick the LSC Funded Provider option. Try to find a law centre in your area rather then solicitors as your kind of enquiry are their bread and butter (as opposed to solicitors' conveyance, divorces etc ). Do this today and call the on Monday- do not wait.
Next; write to your landlord and CTax office of your local authority. Explain the reason for your arrears and inform the that you are appealing the backdating decision. Ask them to allow you some time to deal with it and if they will not agree write again and offer lowest instalements posible.
Fingers crossed and keep us posted!