EON direct debit

Scot_39

EOn Next recalculated my annual DD in April, to use up credit over winter (mainly due to govt EPG discounting).

My estimate of balance at the end of 12m was less than £5.

If used (last 12m use at new Apr charges - credit adjusted for use to letter date ) -12x new DD as the target balance metric.

May be overly simplistic, but that is how I've set my own DD for years - when Ofgem change the prices - normally ahead of EOn -  and they tended to then accept my new levels.
But that was easier before EPG discounts and some very large swings in MR vs SR and so peak vs off peak rate balance on my E10 in last few quarters.

EOn used to auto refund annually if in decent credit (for me with Jun bill - last was sub £200 - but that was c3m use). 
EOnNext in early Mar were offering me a chance to request a credit refund - nearer £400 showing as balance after last months use taken  -  but didn't tell me explicitly about the offer.  I had to look on line - in the DD sub menu iirc - and the offer disappeared when they lowered my DD.  Perhaps me not taking it was a sign I didn't want it ?

They lowered the DD again in Jul - it's now below even summer usage costs last month - so pretty confident credit remaining will reduce very quickly come winter - when the monthly bills more than double.

PS the OPs gas bills are quite high - possibly as a result of age of mum and higher temperature requirements.

But might be worth seeing if she qualifies for any heating or insulation grant schemes (loft, cavity wall etc) to help reduce it.

(My mum in her 70s got both loft second layer and cavity wall done for free - but that was many years ago and under a Scottish scheme)