Residents of a large apartment block in Wallsend are thousands of pounds better off after their landlord Isos successfully complained to energy company npower about some wildly inaccurate bills.

The residents of Diamond House on High Street East in Wallsend could not understand why some of them were not receiving energy bills at all, while others were getting charged very high amounts.

One resident said they knew they were normally a very low energy user, spending only about £5 per week on electricity, but in Diamond House they had racked up a bill for £2,500, which was very worrying.

Several other residents also had more than £1,500 owing on their energy accounts.

The mystery started when benefits and money advisers at Isos Housing were approached by one of the tenants in Diamond House, querying her bills.

The building was only completed in 2013 at a cost of £2.8m.

Other tenants in the 28 apartment building then also got in touch, and the advisers also found that their colleagues in the Development department at Isos had been asked whether electricity meters in the building were providing the right information for the tenants.

Eventually Isos staff met up with the building’s original building contractor Surgo, to try to understand the billing problems.

The partners believe the problems may stem from the original installation of electricity metres in Diamond House, when the fact that the building does not have an apartment numbered ‘13’ (as many streets and buildings do not) appears to have caused confusion when the metres were being allocated to each home.

When all the evidence of inaccurate billing had been gathered together, benefits and money team leader Lee Forrest submitted a corporate complaint to npower with a dossier of evidence to back it up.

Lee said: “It was clear to us that there were very large inaccuracies in the bills being sent to some of our residents – while others were not receiving bills at all. This was hugely worrying for those on relatively modest incomes, who could never afford the inflated amounts they were being asked for – and those not getting bills were concerned in case a large bill would eventually arrive, covering all the months when they’d been charged nothing.”

Eventually, after a long period of correspondence with npower, all the Diamond House residents’ queries were resolved, with several residents seeing huge balances slashed to zero.

Npower has now pledged to ensure all metre readings are recorded correctly, and for the correct flat.

Benefits and money adviser Lindsay Lusher, who worked on many of the residents’ queries, added: “This has caused our residents a lot of worry. People have been doing their best to keep track of their energy use, and they knew their bills were not accurate, but it took a lot of perseverance with npower before we could relieve our customers’ worries.”