Switched provider billed from previous supplier

CDB_20

Hello everyone, 
First time post so be gentle!
I’m just looking for some advice with an billing issue I’m having, hope you can help?

A brief history!
December 2019 no problems with my supplier I’m 18 months into a 2 year deal found on here btw. 

January 2020 my supplier is taken over by a certain sea creature named company.
Switch seems to go through with no problems some meter readings provided between January and June 2020. 

June 2020 my deal runs out I shop around again and find a new supplier.
July 2020 switch to new/current supplier seems to go through seamlessly. 

No problems to date with new supplier.
January 2021 I start getting phone calls from the previous supplier stating without explanation that I owe money, despite paying all previous bills on time and the account closing when I switched to my current provider. 

Following a bit of further investigation I logged into my account from my previous supplier to see a new bill for approx 6 weeks of usage for electricity only from the initial switch to them in January 2020 after they bought out my supplier. 

My questions are 
1) Where do I stand in regards to having to pay them?
2) Given they have/had my original suppliers last bill before they bought my account why didn’t they charge me at the time? 

3) Should I make a complaint given it’s been nearly 9 months since I left them?
It’s not so much the amount being demanded that I have a problem with it’s whether they can/should be doing it?
Thanks
Chris

jbuchanangb

The question is: Have you previously paid anyone for this energy? If YES, challenge it and explain. If NO, pay the bill.

It sounds as though you probably have your records of meter readings and bills paid etc., so check through and figure it out.

PixelPound

You only get charged once for energy. It sounds like when they took over in Jan 2020 the start meter reading differs to that the previous supplier had used.
1) if you owe it you have to pay
2) because maybe readings only came to light afterwards. 
3) On what grounds, they can do rebills, even if it's 9 months after, if new information comes to light.