Bharat Sanchar Nigam [BSNL] — after disconnection request bill is still generated

Address:

Mayat wadi, mahuvej road, old kosamba ,kosamba (r.s),surat, Surat, Gujarat, 394120

I was having bsnl land lineconnection in kosamba dist surat gujarat
My no. Was[protected].
My plan was 59 rs. But after few month suddenly i was getting bill of 250 to 400 rs.
On inquiry they told me that now your plan has changed. But they never informed me or asked me to change plan.
So i asked them to dis connect my no.
They told that your request is registered online.in april.
But still they are generating my bill every month