Return deposit - How do i know if tenant has provided correct final (utility) readings to suppliers at the end of tenancy

I was wondering how do a landlord know / how do a landlord check if utility bills being paid with the correct final readings at the end of a 12 months tenancy before returning the deposit.

I took the final readings together with the tenant (with photos taken) .When i checked with her a few days later if she has provided the final readings to the suppliers, she said her account has closed and when i pointed out there should be a final reading on her final bill, she did not reply my text message. When i listed all the final readings that we took together in an email to her to ask if she could confirm that she has provided the listed final readings to suppliers, a few days passed she still not reply. I have sent an email to the gas & electricity company (they do not have a phone call system at all) to check but no reply.
What should i do?
Any advice will be greatly appreciated.
Thanks in advanced.

Write to the utility company with name of tenant ,address, picture of meter readings, the contract and meter readings and meter serial number in the image and ask them to close the account in her name and send the company her forwarding address.
You will need to start a new account in your name.
If the meter is a smart meter the company will have the readings anyway.

You make sure the utility contracts are in the tenants names by closing your account when they move in and opening new ones when they leave. That way you don’t need to worry as its between the tenant and utility companies.